I agree that someone might not tell her mom she was meeting with someone, but in this case she told her mom she was going jogging. That's not a case of "not telling mom" something you want to keep private, but a deliberate lie.
I just don't see Vanessa lying to her mom. There is just absolutely no vibe I get from Vanessa that she would outright lie.
But it's just my opinion, nothing more. No use repeating it, I supose.
I understand and respect your perspective. But that's not quite the way I was piecing it.
We know Vanessa had a routine, she came home bi-weekly and she always took a run or walk when she was home. (That rt appeared to be one route she would go, but not her only rt)
When she's home, a friend reaches out to her and wants to talk, my theory is perhaps they were going through something. so kind hearted as Vanessa was, she was trying to be helpful. Perhaps for privacy reasons or if her parents weren't fans, or they just didn't know about him and she didn't think it was really important to explain it to them (because obviously she didn't think her life was at risk).
So she figures she will just meet with him when she normally goes for her run. As its in her normal routine it won't seem suspicious and no one will ask any questions so she won't have to bother to explain. She also won't have to ask to borrow a car because she can just run there.
She figures (theory) go out and help a friend, not have to explain it to anyone....i''m not doing anything bad....I'm just trying to help a friend...and I'll be back home at my regular time anyway....no harm done.
I'm sure she's the type had her mom directly been suspicious of something and asked she wouldn't have flat out lied, but her normal routine gave her a way to simply evade the truth in a way that seemed pretty harmless at the time.
It's not like I'm suggesting she went out into the woods or got picked up in a car to hook up or get high.
I'm suggesting she simply may have avoided telling the whole story simply by just sticking to her routine.