Does it work at all if you pivot or change the course of the conversation? For a simple example, she keeps talking about how funny he is and you say "speaking of funny..you wouldn't believe what happened to me the other day." Keep changing the course of the conversation until it's more give and take. I understand where you're coming from. I have a longtime family friend who talks my ear off and I eventually either have to vaguely agree with them and walk away or say "well, I have to x...see you later." Good luck and best wishes.