Yeah, technically (according to wedding ettiquette) asking for money is a big no-no. BUT I am assuming that the people that you are inviting are friends and family, who should care more about you and your soon to be hubby than ettiquette that was put in place when wedding were more about the parents of the couple than the couple themselves, and when the wife was moving from her parent's house to her husband's house (hence the need for all the housewares). I think that while not following wedding traditions, it is a really cute idea, and the fact that you are asking for something for your kids to enjoy as well, rather than leaving them with a sitter and going to Hawaii is honorable. If any of those invited to your wedding take issue with that, you shoudl tell them to bugger off.