How about her seeing therapist?

Is she raving and ranting about her ex or about her child being upset? I'd honestly shut her down about too much talking about ex. That's what therapy is for. I mean once in awhile is ok but not constantly.

If however she talks about her child I am not sure about shutting her down. If she can't complain to you about her kids being in harms way, then what kind of relationship is it?

I and my husband keep complains about exes to a minimum but we don't stop each other ranting about kids (we don't have kids together). If either one is upset or worried re kids we are free to rant away.