My personal feeling reading this and from what you’ve written before.... she should have let you move on when she went away. At least temporarily. If you’re needing regular therapy, you need someone there, not just calls or email. It seems very selfish of her to put her session fee ahead of your wellbeing.
If you’re ready to, you could begin meeting with other T’s then tell her if you find someone you really click with.
I also don’t think that there’s anything wrong with asking her what her plans are for returning. You need to know! And I honestly can’t believe she’s been billing you for any of these calls but especially the emails.
This is just my personal feeling and how I would want this for myself, I’m not claiming to be qualified to give you advice, but I’d be off if it was me!