Update! She started using the bathtub as a litterbox in front of me, so I picked her up and showed her the litterbox. She wasn't super into it but finally used it after I kept picking her up & out of the tub. Then we just filled the tub with an inch of water for a few days. She's using the...
I just realized I never actually asked a question! Any ideas on how to solve this situation? Everywhere I look it's either a cat that's not using the litterbox at all, and other people have suggested putting the litterbox outside, which I would never, ever do. They're definitely not outdoor cats.
Home setup - 1br with two cats. One is about 2 years old & we've had him for over a year, the kitten is 4 months and has lived here a month. They both seem to love each other, they were grooming each other and happily eat together. We got her because I had to stop working from home and figured...