I can't tell you why she doesn't bring things up if you asked her to, but even if she is uncomfortable with it, it is your session time, you are allowed to talk about this. If she dislikes it, she will have to deal with that somehow and not let it affect you.

When I bring up anything therapy related, I am always prepared to spend the whole session on this. I'm usually scared of these conversations, so I start with something like "I want to talk about something concerning you, but I'm scared". Then we have a short discussion about why I'm scared, where T tries to take that fear away and then he probes for what the actual issue is. I think any halfway decent T will try to talk about the relationship if you mention you have an issue with something there.

It's always scary to bring these things up, but it's better than just sitting on it and not being comfortable with how it is now.