So, I recently started working and so I'm new to the workplace.
I came in around the same time as the girl who sits opposite me (she has about 3 months on me). That being said, my first two weeks in, I had lunch (in a group of 4-5 people) and talked with her a few times after work on the way to the train station, etc.
After the initial weeks, I started bringing lunch to work and ate in mostly to save money and didn't join them for lunch (they didn't ask either). Now, when I say things at the coffee machine or just random conversation to her, she just nods and quickly leaves, or says nothing at all when we cross paths.
Additional info: during an office half day, I walked with them to grab lunch after work, during the whole walk they didn't really talk to me.
I'm not sure why her behavior changed and I don't have much issue with that. But now I have a project where I have to work with her and even when we discuss about work she will keep it short and prefer to discuss over skype messages than in person (did I mention we sit opposite each other?).
I'm afraid that if I try to initiate conversation too much (even for work) it would make what she already thinks worse (I have no idea what tbh).
Example of a skype conversation:
Me: [details about the project], hope you're feeling better (she was sick)
Her: OK, I'll do (part 1).
Me: Thanks a bunch I'll focus on (part 2)
Her: Good.
Question
Is there any way I can approach her without making things worse and finding out what happened?
Note
I have no romantic interest in her, I just want to make my work life better.