On Eros, I counted 5 that advertised as available to couples, only 1 of these ads specifically says available to women. If I ever get to Houston, I hope to meat Kristi, who adverts as couples friendly. I believe she is a member here too.
www.eccie.net/providers.php?do=view&id=82416
Added: also, in keeping with the spirit of the OP, not only do you need to find a T-girl that is couples/female friendly, you need a top. Being female friendly you'd think they'd have to be a top but never assume anything.