At my wits end over spraying, should I rehome?

I have a female cat who is around 5 years old and I have had her for about 3 years now. She is a great cat, loves people, and is extremely cuddly, but she has always been somewhat territorial and has a major marking issue when she feels threatened. This is usually not a problem as long as she isn’t around other cats…but long story short, we had a baby last September and she has begun displaying these behaviors again. She is not aggressive with my daughter at all (actually mostly avoids her) but I can’t think of anything else that would be triggering it. She’s currently on fluoxetine and we use Feliway diffusers, yet I have seen almost 0 improvement. At this point I’m fully ready to rehome her. She recently peed on my baby’s car seat and that was basically the final straw. We have confirmed with the vet on two different occasions that this is purely behavioral.

I’m fighting a losing battle here and I feel as if our home is no longer the best place for my cat. With that being said, I don’t want her to end up being euthanized over this issue. Is there a rescue in the southeastern US for “problem cats” that I could take her to, or does anyone have any tips on other things I could try for this issue? I even use enzyme cleaner on the spots she marks in and she STILL keeps going back to them.