My t does not charge extra for emails or phone calls less than 10 minutes. However, I've talked to her for up to half an hour before, and she didn't charge me for that. I also don't call her all that frequently (she'd prefer I call her more frequently than I do).

If I've scheduled a call for her, then she charges a portion of her regular fee, depending on the length of the call...but that's only when we'v scheduled something and it's a half hour or more.

I think that if you really feel the need to pay T for her time, you certainly can. However, you might ask her about it as well and maybe explore where your need to pay is coming from. Is it really just that you feel she's spending extra time with you so you should pay for the service, or is it part of that need to pay so that she'll like you?