Jokes about your friend's new in-laws won't go over well, especially if a) the jokes aren't funny, and b) the family is footing the bill for the dinner and booze you're enjoying.
Even if you've heard horror stories about the groom's mother from your friend, remember that this woman is one of your hosts. A dig like, "Don't worry, Ashley. I've got some scissors you can borrow if you need to cut the apron strings" might seem silly to you, but this is an emotional time for the families. Instead, give them a positive mention in your toast, and let them know they did a great job raising their son or daughter and how lucky you feel to know them and be part of their lives.