Hi Granite!
I'm glad you had a good vacation.

Have you specifically asked your T about changing days? Have you said "I want to change the day of the week I see you?" She might be waiting for you to speak up about what you want. You can talk about how it sucks that the sessions keep getting cancelled, but she can't know that you want to switch if you don't say it. If you don't say anything she may assume that you don't want to change days.