I think the fact that she is your couple's counselor makes it tricky. I believe they have to be careful not to show impartiality, which texting for extra support might be. So, if you ask her and she says it's not her policy to exchange texts, this could be why.

Regardless, I think if someone is going to text or email, s/he needs to be really clear and on point about the message and expected response (if you want to know an answer to x y or z, state it clearly). It's really easy to miscommunicate and end up feeling worse.