For this game, you need an index card for each guest and something for them to write with.
As guests arrive, hand them an index card. Ask them to write a question that a new mother might ask (for example, “how can I stop my baby from crying?”). Ask the guest to remember their question for later, and collect the card from them.
Later during the shower, shuffle the cards. Pass one to each guest, face down, and tell them not to look at the other side. Have them write the answer to the question that they wrote down when they arrived. Then, pass the cards back to the hostess.
The hostess then should read the question from the front of the card and the answer from the back. The combination of mismatched questions and answers is hilarious!