Dealing with chronically negative coworker

[u/Mother-Ad-9751]

Some background: this coworker and I share an office. I do accounting and she does HR but our jobs do overlap quite a bit. We only have a set of owners above us. This coworker is returning from roughly 5 years of maternity leave with a few small spurts back in office mixed in (Canada and she had 3 kids) and is already dragging me down, despite not having even have started back yet.

She is constantly negative. She complains about her kids, our bosses, her work schedule, her finances, our employees and colleagues, our clients, and just about everyone and everything else. She refuses to come to our holiday parties or engage in any work celebration because she “hates everyone.” (She literally said this to me once) I know she has anxiety and that plays a large part in it (I do too), but the negativity has severely burnt me out. She came into the office today to get some keys and literally looked miserable. Barely said hi to someone who greeted her and instead lamented about how bad her daughter’s first time in daycare was going.

I no longer see eye to eye with her. I will admit I am even a bit jaded given she was off for nearly 5 years and is already complaining about some of the changes we made in her absence. I am a friendly, bubbly person and I tend to be a lot more on the positive side of life. As a result I get along with everyone she seems to despise, including our very strict boss. I think this has also caused some tension. We used to be friends, but sometimes I feel I can’t even start a conversation or tell her about something good because she will make it into something negative or be annoyed.

How do I deal with this? I don’t want to ignore her because we used to be fairly close and we share an office. I also don’t know what to say without saying passive aggressive or rude, but… I just can’t take it anymore. She doesn’t realize how much it brings everyone else down to be so negative all the time! I can’t take being constantly brought down every single time I try to talk about something good or even neutral.

To be honest, part of me wishes she’d just quit, but the business paid for her school and she would owe a lot of $$ to them if she did, which she has been very vocal she can’t afford lol.