Karamo tells someone anxious about their partner that the hypervigilance comes from past trauma, not from real betrayal. Stop looking for proof of wrongdoing. Let them show up for you, and expect the same in return.
I believe the trauma that you've been through and the experiences you've had is keeping you on high guard, which I fully understand. But it doesn't sound like she's cheating on you. It sounds like she's there at the house and she wants to be there for you. I would suggest that if you really do love her, you gotta start letting her in and you have to stop looking for something that's going to make you think she's doing wrong.
What is it that we can work on? What is it?
There's nothing you, in this moment, you need to do. This is him. This is him. This is an opportunity where you showed up for him and I've seen it. He needs to show up for you now 'cause you deserve someone to prove to you they love you as well.