This is all TOTALLY my opinion only, but here's my best guess on Delmar pieced together with what we know (feel free to challenge/correct any and everything)
While the girls are out at various parties, we have Sherrill finishing furniture at home. She most likely would have changed clothes from graduation if she was stripping chairs and hanging wallpaper border, right? You would THINK LE would have been able to find and pinpoint these clothes in her hamper due to wallpaper paste/varnish residue and even smell. But I guess that info wasn't released.
So she's probably got on refinishing clothes, she's working and taking occasional breaks to talk on the phone to friends (and probably smoke). I'm looking for more info regarding which room was being wallpapered and where the chair was being stripped but unless it was all happening in her bedroom, she most likely opens her bedroom window, the solid front door, and maybe even Susie's sliding door to air out the house as the fumes would be pretty unbearable without doing so.
Cinnamon gets out at 10:00pm. Possibly Sherrill is still on the phone with the 9:30 caller so she doesn't notice. Neighbors "put him back over the fence"- I'm guessing there's a hole maybe between the neighbor's shared back fence? He apparently gets out often, since they immediately knew him and what to do with him- no walking around with the dog or bringing him to the door like they would if this were something new. I saw where there was possibly a doggie door (conflicting statements about whether it was there then or added later) but if the dog gets out of the fence often, you'd think Sherrill would have made it inaccessible until the fence hole was fixed? From photos, she seems to care a lot about this little dog. She then talks to another friend at 11:00. And that was the last person to talk to her that we know of.
Bartt says she slept in the nude I think, so she would have definitely been that way this night if she had gone to bed not expecting company. And since Joy's testimony states that the girls were planning to stay with him until 2:00am when he revoked the offer, we can at least infer that Sherrill probably wasn't aware they were coming. I don't think Janelle's was ever an option Susie and Stacy considered due to the evidence we have. My opinion only. If the doggie door wasn't blocked, I'm thinking Sherrill may close her bedroom door at night to keep Cinnamon from getting out while she's sleeping.
Ok, so girls arrive at Delmar, probably around 2:30-2:45. Maybe Sherill is still up but in bed reading. She hears them pull up, and if she's in the nude, maybe she grabs the first thing she sees which perhaps is the dress from graduation? I could see her leaving it out to be dry-cleaned. They go inside and are immediately smacked in the face by the smell of varnish/wallpaper paste/new wallpaper. To someone with recurring migraines like Stacy, this would be a nightmare sleeping situation. But Sherrill and Susie seem like sweet understanding folks, so maybe Sherrill once again opens the window and back door to get some additional fresh air inside--and Cinnamon once again goes through the fence hole and once again the neighbors put him back over. It's now 3am. Since I'm 99.9% sure the girls arrived at Delmar and this is a tight time frame, Cinnamon's escape at 3am makes me believe they were up and awake at this point.
There's one bathroom so Susie probably lets Stacy use it first because she's company. Maybe Susie turns the tv on the way she likes it, drinks a Coke and has a smoke, talking to her mom about the night while she waits for her turn. Stacy uses the first washcloth, gets her makeup off, undresses (possibly putting on some sweat pants or wind shorts of Susie's to sleep in) gets in bed. Then because we have two makeup stained washcloths, it's likely that Susie at least gets to the point where her makeup is off (if Sherrill is truly a tidy person, I can't see her leaving her own makeup cloths out on the sink). But because her pink shoes from the night and Sherrill's floral dress are missing according to Charley project, that tells me that maybe she didn't get much further than this before the perp(s) busted inside. We know that Cinnamon ends up loose INSIDE the home and that the doors are all closed (not locked but closed) when found the next day IF Janelle is to be believed. Because Cinnamon had not escaped again by 12:30 when Janelle & Mike get there, this confirms to me that he either didn't know how or was blocked from the doggie door. Again, this backs up the theory that a door was opened at some point again around 3am and then closed back up before the perps left.
So the perp(s) get inside somehow, Stacy is in the bed, Susie and Sherrill are possibly still dressed. They gain control of the women somehow (probably easily with Sherrill/Susie if one of them was threatened) and possibly corral them to Susie's room as the living room has a huge picture window facing the street and they will need some light to keep control of the women. Now they'll need to get them out to the getaway vehicle. I tend to support the van sightings because I believe it would take at least two, if not three perps to pull this off and then you have the three women- six people is a lot to hide making your escape. If the backyard is fenced in and the garage door is dead bolted without an obvious key, the front door becomes the only option. LE also tells us they are confident they left through the front door. But right now, the porch light is on and that would be shining a spotlight on the exit pathway. I simply cannot see an experienced criminal capable of pulling this off who wouldn't turn the light off to take them out. Now here's where I found something interesting but unconfirmed. I read in one thread posted by hurricane that the previous home owner said this switch was "sticky". That a lot of times flipping the switch wouldn't turn the porch light off as intended and vice versa. So if this is true and the light switch isn't working, the only way to disable the light is to remove the globe and at least twist the bulb. Maybe the perp does this and puts the globe down on the porch intending to replace it when he leaves. But it gets knocked/broken/stepped on by one of them in the process of leaving? OR, he accidentally breaks it trying to get it off and cuts himself in the process leaving some evidence behind?
As for the parking situation and witness testimony: Nigel said Susie usually parked directly behind Sherrill and the paper person said parking changed between 3:45 and the next afternoon. So if this is true, that means the women were still inside the house at 3:45. IF Susie was parked in her usual spot behind Sherrill and Stacy was pulled up to the inner portion of the semi-circle, thats a LONG walk with hostages to get to the pulled up van. So maybe they decide to rearrange the cars and gather the purses in order to find the keys. Maybe they don't know the women well enough to know exactly whose purse is whose, so they'll need to gather them all. Carefully pull out the wallets and keys to be sure he doesn't leave evidence. Don't worry about putting them back inside and closing them back up, too risky.
Perp two goes out, backs Stacy's car up. He pulls up as far as he can and backs Susie up too, only he doesn't have big of a turn radius from there so he ends up kind of wonky in the grass. Perp one watches this through the blinds in Susie's room. Van is backed in, into the spot behind Sherrill's car. They take women out through the front door, load them in back of the van, turn the walkway light back on, replace the porch bulb, and leave.
