My MIL expressed an opinion on every part of our lives. DH used to bark at her and tell her to keep out of our affairs so there was no need for me to do it, then everyone carried on as before, MIL took it in her stride and so did we, but her opinion was never actively sought. My own mother would pick up her teacup and go into the other room if matters she considered private were being discussed taking the GC with her. My father would only venture an opinion if he was asked for it, prefacing his comments with "well of course you know your own business best, but as you've asked me...". and then not questioning the decision we made. Which is how I've played it with my children. Anya has the right idea, in my opinion, although, of course, "you know your own business best"!