Actually watched this the day it arrived, and really pleased I did. Having seen the trailer for it on another movie, I knew it had to added to my rental list. Although single myself, I've worked with enough people to know quite a bit about Mother In Laws to put me off them.
Cannot recall seeing Jane Fonda in a movie since Barbarella, but her comedy in this is first class especially the nut allergy and her "don't leave/stay with me" supposedly girly friendship with her new daughter-in-law played by Jennifer Lopez. This was only the second film I've seen Lopez in (the other being Angel Eyes) and her move to comedy was a good one, so wouldn't hesitate to try others. Also liked the personal assistant character although my only complaint would be some of her lines were not that clear leaving the viewer to work out what she said. The appearance by Elaine Stritch was a total surprise when she went up in the cast, couldn't think what character she would play in this type of movie, but you'll have to rent it to find the connection. Overall a really enjoyable film, would highly recommend.