What is up with my 40m girlfriend 39f?

So I’ve been in a relationship for a couple of months with this lovely lady. I only see her at weekends due to work schedules/kids etc. She usually comes to mine for a few hours on the Saturday then goes home then the same on Sunday. We have had sex a couple of times. Shes met my family but Ive never been introduced to hers or even her friends. I know she has kids and separated. She wont do anything with me., like go on dates etc. She doesn’t eat in front of me and wont even use my toilet. Could I be her rebound? Like why won’t she eat infront of me or use my toilet? Maybe like a mental issue?