All JMO-- Possibilities/ideas: If an abductor is involved, that is likely someone who met her very, very casually; she viewed him as pretty insignificant & may have seen what appeared to be troubling signs in his behavior; she didn't take him or any exchanges with him all that seriously; he knew it, really resented it, knows she's a beauty queen with a bright future ahead of her and he's got some issues, so he was stalking her and jumped at the chance when he saw her come outside the building. For what did she come out, who knows? Forgot something she needed in the car, maybe her lunch if she packed one, wanted to do a "fridge cigarette" (ice cold diet coke break), or/and just needed a bit of fresh air, what have you.
And she is a beauty queen, she's definitely noticed by passers-by. This being the case, might worry about visitors to the facility, and from what i can see, visitation at this facility is NOT restricted, it's listed as open 24 hours (??with no cameras, not sure if this is correct, but that's what I got when I searched). Maybe the hours just aren't started explicitly anywhere online, though. But if visitors can still access, and some visitor or co-worker became fixated on her, somehow got her number, she may not want to make a fuss over it because she has only recently started the job, and she perhaps really wants or needs to keep it and not make waves over what she would view as close to nothing.
And again because she is so noticeable, it's also possible it was fairly random, although far less likely, again all jmo.
The most optimistic scenario here is that she took off, perhaps with someone or with help from someone she knows & is doing just fine somewhere, those pageants are a lot of pressure, to my knowledge, and maybe she just felt she'd had enough and needed a break. It's the beginning of shift, so if she's not enthusiastic about the position, and she's in any way stressed over the pageants, and/or has this unpleasantness to deal with with the phone calls, maybe she took off. As unlikely as it might be, i'd actually hope for this scenario at this point (particularly if they're searching the arboretum) because there's room for a happy ending there. Understood the taking off scenario may not be something anyone would normally "want," but if they're calling in homicide, I really and truly hope it (the taking off) is the case, in the biggest way possible.
As far as calling in homicide goes, I will continue to hope for the best and think the best is still quite possible. But just noting, I know LE's focusing on the arboretum, but what I'd fear far more is Wissahickson Valley Park (14 mins from arboretum), to my knowledge, there have been remains found in/near there in the past. Again, I continue to strongly and optimistically hope not.