AITA for not cleaning my cats' litter boxes often enough (roommate).

AITA for letting my litter boxes go unchanged for sometimes up to 3 days?

I (30f) was previously living alone with my 3 balls of fluff in a one bedroom apartment. I genuinely thought changing my cats' litter boxes two to 2-3 a week was normal, but my new roommate insists that I should be cleaning them out every day. I have 4 litter boxes in my walk in closet. 1 in each corner. I've always had more litter boxes than cats because that's how my parents owned cats (crazy cat lady runs in the family I guess). I only notice the smell when my cats go to the bathroom recently and l'll open a window for a few minutes to clear it out. A one bedroom is admittedly too small for my babies, but my apartment has a large living room and a decently sized dining room/kitchen. All 3 cats are rescues and I like to think they are happy here with me regardless of our small space.

My friend Elizabeth (FN) (36f) has been going through a messy divorce. She ended up having to move out of her ex husbands large house and move into her mother's one bedroom apartment along with her 3 children.

Elizabeth has been complaining non stop to me about her mother and how difficult it is to live with her. Her mother is messy, bossy, and is constantly confusing her children by teaching them about a religion they don't follow.

I could see how exhausted Elizabeth was and offered her and her children my living room while she gets back on her feet. Her kids are absolutely adorable and I love watching them. She would have basically the exact same set up living with me.

At first things were great, but recently she has been complaining about the litter boxes literally every day. Even on the days I clean them out. She insists that I'm not cleaning them often enough and when I told her my point of view, she said that maybe cleaning them out 2-3 times a week would be fine if it were just one cat, not 3.

I'm doing my absolute best to accommodate her, but I I'm starting to feel resentful towards her. I still haven't changed my routine of cleaning the litter boxes, but I don't feel like I should have to. My apartment is spotless besides the closet. I've purchased candles, fabreez and a different brand of litter to try and combat the smell (again I don't smell anything at all unless one of the cats has a recent bowel movement, but maybe I'm nose blind?). I keep my cats in my bedroom at night out of consideration of her and her kid's sleep. I charge her less than a third of my cost of rent because I know she's struggling + I'm in the bedroom so I think paying less in rent is reasonable.

I finally cracked when she complained yet again yesterday and told her that if it's that unbearable, she should move back in with her mother.

She started to tear up and left to pick her kids up from school shortly after. We still haven't talked about it.

I'm starting to feel incredibly guilty. She was there for me when I first moved into this apartment and was broke. I had no furniture. She bought me a bed so I didn't have to sleep on the floor. She drove me to and from work for an entire month when my car broke down.

Part of me thinks that cleaning the litter boxes more often is a small compromise so I should just do it, but another part of me is so completely frustrated with her invading my space and acting like my mother telling me what to do.

So reddit, AITA and how can I bring this topic back up and set boundaries without being rude? I know I should apologize, but I also don't want to let her boss me around. The litter boxes are just one of the many things she nags me about, but it's the only cleanliness related request. She's sometimes upset with me for wasting my time playing video games or she will try to tell me how to spend my money. I feel like a teenager again and not in a good way. I'm starting to wonder how long it will take for our friendship to break. We've only been living together for 3 months.