No, I don't give her any time limits or even imply anything like that. I know that her discussions usually don't go too long anyway so I don't worry about it. In part, I know she is trying to do her part to improve communication between us, but I really don't think she is comfortable talking about intimate things between us. So it is either the kids or her work.
Lately we have had issues with the kids and their friends, the typical teenage girl stuff, getting into one another's business, gossip, hurt feelings, boys, etc. I told W this is all drama to make themselves feel included, important, etc, and how one girl seems to always be the "touch stone" for everyone, and so gets most of the drama.
I think W also sees that she creates drama at times, though she has not said anything to me, because her dramas seem to have declined in frequency. For now, and especially at the end of last school year, her work turned into her drama. So I listen to her and sometimes even try to offer my POV.
I don't expect her to respect me for listening to her school issues, I only expect her to see me doing my part to accommodate her attempts to improve our communication. I do believe that at some point the allure of the drama will die down and she will feel more comfortable speaking about H/W topics.