Hey granite, since you're having to pay for the time taken for heart surgery and recovery (which, honestly kind of shocks me), how would you feel about asking to keep those sessions, but have them over the phone instead? It would not be doing you a favor for her to do that, since you're paying anyway; in fact, I would think she'd have to say yes. Another option is emailing back and forth for the hour.

I would not like hearing about my therapist wanting to move my time around for another client to have a longer session, either, btw. Maybe it's for a new client (sometimes first sessions are scheduled longer) or administering some kind of test or eval (if she does that) or it's for a family, or some other circumstance. Regardless, you don't need to hear about it.