Yeah, what Candace said. It is all behavioural. She is stressed and feels the need to mark her territory.

Vita is my Queen here, thank heavens I only have ONE Queen! She started peeing in January, when Tommy & Tuppence arrived. For months, I thought it was dear Ozzy, as he was an old dog with no house training. Finally leanred the "truth" in September. Since then, I've used Catty1's method, a strip of fabric over her collar, and spray the fabric with Feliway. If I spray Mon, Wed and Fri, we are good. If I miss a day, Vita is marking territory again.

Thank goodness, Vita is not peeing on furniture. She will mark any piece of fabric she finds on the floor - from pet beds to catnip mice!

Can you keep her in a room with just a few kitties for a while to help her calm down and adjust? I hope you can find a solution, even if it means rehoming.