Claire has been trying to think of ways to make money. She wanted to get a job like her big brother but was devastated to learn that you must be 16, not 6. So being the creative child that she is, she elected to enlist the help of her hamster in her quest for cash.
The sign actually says "Come here at the hamster can jump." It just looks like "Come here at the hamster can limp", with limp spelled with a 'y'.
I think it's possible that I have spent too much time in the house lately. Because there really isn't anything funny about pimping out disabled hamsters, is there?