Speech therapy

What is normal to expect from a speech therapist? We are supposed to have 2 appointments per week at home. She cancels about half the time due to illness. That's frustrating, but I appreciate her not showing up sick and she can't help being sick. However, she has also had two times the past month where she has "forgotten" personal appointments and cancelled on us to keep her personal appointments. So that plus cancelling due to being sick is really adding up. And it's hard getting two kids ready for this appointment (I'm a sahm to another child as well), only to have it cancelled an hour beforehand. Y'all know how it is- if there's an appointment, the wheels have to start turning for that at wake up time.

With all that said, my child is very comfortable with her and that counts for a lot. I know we "should" be able to count on professionals to keep their appointments, but maybe most speech therapists are just informal like this? I don't want to switch speech therapists and risk getting one my child isn't comfortable with, having to waste weeks while my child warms up to a new one, etc if the reality is that this situation will probably happen with any speech therapist. Thoughts?

If it matters, this is private speech therapy, not state-provided.