I talked to some student friends, and they all said this was strange/mean/unacceptable.

I decided to confront her. My goal was for her to say she was sorry. When I confronted her, she gave a bunch of excuses as I kept pressing her. Basically, she was really busy and she forgot, or so she said. I expressed my disappointment in that we couldn't teamwork and communicate better. I asked her if I could have done something differently, and she actually said I should have asked her several times if she already did her work. Then finally, she admitted that she could have let me know. She then promised to do the work asap and I asked her if she was happy on how we talked this out, and she said 'yes'.

Later, when we were near finishing the report and she gave me positive feedback on my new addition, she started to talk about it again and about how she thought others missing their deadlines by one day caused her to miss hers by weeks. But she then also said she was sorry she caused me inconvenience. I then said I was sorry for being a bit angy-ish and she said 'no worries'. I then asked if she was doing ok, with all the busy stuff going on and she said 'yes'. I then managed to get her to tell a bit more about what she was busy with.

So I got the apology I wanted and for sure there are no more hard feelings. Maybe she respects me a tiny bit more now. But I didn't get her attention, like I would have liked. She still doesn't put herself in my orbit or seek me out to chat or have lunch.

Basically, I faked being as busy as she was when in fact I had only a few things going on in my social life, trying to make her think she caused a big problem and making her say she was sorry. But I talked a fellow student into doing the work for us. So now not me and not my romantic interest did all the work. That's not how I usually do stuff and it feels a bit dirty. I still did a lot of work and this third person was happy to help out. But it was all a trick.