It seems like your T maybe isn't as engaged with her work as you would like her to be. Maybe she used to be more engaged but now she is transitioning to retirement. Or maybe she thinks part-time work only requires part-time attention. Whatever the reason, it sounds like you aren't really getting what you need from her.

I think the situation is unfortunate, particularly if you don't feel like she is being supportive enough about the breaks and if you don't feel like you can broach the subject with her. My advice would be to try out some other T's and see how that goes. Maybe you can schedule those appointments ahead of time for the weeks when you know your T is out of town. You don't have to make any decisions now, but maybe this will help you get into a therapy situation where you aren't constantly questioning your relationship with your T. That seems like a necessary ingredient of good therapy to me.