My coworker is driving me nuts

I’m 1 year into a new job and I was sitting by myself for this time, my nearest coworkers were about 15 feet away so it was easy for me to plug in my headphones and work away.

Someone who was on mat leave has now come back and she sits beside me. She’s nice and all she’s just so annoying.

She doesn’t stop talking even when I put my headphones in. And when she is quiet, she makes irritating sighs and groans. When I go to take my break she takes hers too and she talks the whole time and I just wanna sit by myself in silence. Having conversations with her is hard because she just talks over you and I just sit there and listen the majority of the time because you can’t get a word in. She even plays reality tv shows on full blast at lunch where people are yelling in the episodes and it’s so overstimulating. Like I’m trying to RELAX!!

She’s only working 3 days a week right now until the summer is over but I am already exhausted by mid week and I am dreading her working full time. And she gets me to do parts of her job she doesn’t know how to do and has even asked me to do her work when she’s off. I don’t really want to be doing someone else’s job on top of my own, she chose to work PT and I don’t think it’s fair for me to do her work when it can wait 48 hours. I don’t know how to deal with this and I am definitely going to lose my cool on a Friday or something.

If anyone has an ideas please let me know, I don’t know how to fix this.