here's a rule you may want to follow:

If she texts about the kids, obviously communicate with her, anything about the kids is definitely responding to

If she texts just to take your temperature or shoot the $hit, take your time responding, in the end it's up to you if you have to respond at all but don't feel obligated to maintain the "gay friend" relationship

(nothing wrong with being gay if you want to be gay, just saying) ;-)