One thought would be for you to figure out what boundaries would seem reasonable and suggest them to her. Like, "I feel like I'm e-mailing you too much and need some boundaries. How about a limit of x number of e-mails per week?" (or certain number of paragraphs, etc.) And then ask her to help you stick to that?

The problem I've encountered with e-mail is therapists who keep saying it's fine, until...suddenly it isn't (this has happened both with ex-T and marriage counselor). Like suddenly, they told me I needed to reduce outside contact. And this was when I had checked in with them numerous times to see if it was OK. I'm not saying this will happen to you--but I'm sure it would be much better if you were to figure out boundaries for yourself before your T might ask for a reduction--because it hurts like hell for them to ask you to reduce contact...

And I completely get the appeal of e-mailing. They would suggest I just journal instead, but there's something about actually wanting to hand the thoughts off to someone else, even if they don't respond. Current T charges for longer e-mails (and sends a detailed response), which annoyed me at first, but it really helps keep it in check, like I'll only send something if I'm really struggling/in a bad place (a couple times in 4 months). It's kept me from getting into that habit with him. But once you're in the habit with someone, it can be hard to break...