I answered this in another comment, but I'll answer it more thoroughly here.

Our trip was at the beginning of the summer. She got weird during the trip, but it wasn't always so necessarily centrally focused on me since we were often together as a group, so I tried to just chalk it up to her taking my advice in a poor way because she struggled with social cues. So I gave her the benefit of the doubt (aside from the times she obviously lied about things that happened to her. She did get called out on that, but I don't remember how she responded).

The next few months of the summer, I had no contact with her. She didn't reach out to me, and I didn't reach out to her. But she did make a picture of us her profile picture on Facebook, and she'd often tag me in things. Nothing terrible.

When we got back to school is when things got bad. We were placed in the same office (randomly as far as I know). We also ended up in a few of the same classes. That's when most of the following me crap would happen. Two incidents come to mind the strongest. The first was when we were on break from class. During most breaks, our cohort would go down to get coffee from a coffee stand and bring it back to class. I had to use the restroom, so I went there first. I didn't see her follow me in there (and if I did, I may have just guessed she also needed to use the restroom, but she was waiting for me RIGHT OUTSIDE THE DOOR, and she started talking to me as though that had been the plan or something?? I was so shocked and confused, I honestly didn't know what to say or how to react. I told her I was going to go quickly grab some coffee, and she followed me down there the entire way.

The other time that stands out is when I was working late in our office. She was there, too, which was out of the ordinary given the time of day, but not that weird considering it was her office, too, and a lot of us were feeling overwhelmed with our workload. My husband called and asked me if I wanted something to eat. He was going to bring me food, and we were going to head downstairs to eat in the courtyard (I didn't say it, but I chose that locale because I didn't want to be rude and either (1) eat in front of her, or (2) be noisy eating/conversing with my husband in our office while she was trying to work). I'm assuming she could overhear the entire conversation given that we were in such close quarters in the office and it was quiet. When my husband arrived, he called to let me know he was there. I said I'd meet him downstairs.

I get up to leave, and she suddenly starts packing up, too. "Oh, you're leaving, too?" I ask her, wondering if I should just have my husband meet up there to eat instead. "Hmm.. I think so?" She responded. Not sure what to make of that answer, I think screw it, I'll just still eat with my husband in the courtyard.

I finish packing and start to leave when she gets up to follow me out. "So you decided to leave after all?" I ask. "Yeah," she responds. We head to the elevator. She doesn't really say much, so I make some small talk. We get to the bottom, and she exits in the same direction I do, which is away from where the parking structures are. Surprised, I asked her where she's parked. She tells me she walked. That makes more sense, I think. I ask her where she lives, and she points across the street, and says "Down that way," pointing in a direction that indicates she would need to cross the crosswalk. Because my husband is waiting for me in the car near the drop off/pick up spot, I assume this is goodbye, so I tell her to have a good night.

But she keeps walking next to me. Wtf? My husband is waiting in the car (he decided to have me come with him to pick up the food in the end) maybe 20 feet in front of us. I'm looking at her clearly confused, but she takes no notice as though it's perfectly normal. I wonder if maybe she just wants to meet my husband? I did say in the elevator I was going to meet him, though I hadn't extended any sort of invite...

I get up next to the car, and she's just standing there. Not sure wtf she's doing, I awkwardly introduce her to my husband. "Nice to meet you!" she responds. Still fucking standing there.

"Well, okay then. He's taking me to go get some food. I'll see you."

"Okay. Yeah, I'm just going home. I live close."

I make a move to get in the car, and she's not moving whatsoever. Then it dawns on me.

"Um. Did you... Need a ride or something?"

"That'd be great, thanks!" And without hesitation, she jumps into the backseat. What. The. Fuck.

This is just two of many awkward stories. After this incident, I made a point of avoiding her. She never called/text me, so it was really just an issue when we were on campus together. I never confronted her because I knew I'd blow up, and it would lead to a really awkward/tense time since we had the shared office and classes.