Nipping at the ankles can happen for a number of reasons but in this case it's possibly a playful reaction your kitty has as it wants to hunt and pounce. If Bobi is young, it should subside after some time if not encouraged to play with hands or feet. Have your daughter keep a toy on hand to direct the cat's attention.

If play gets a little out of hand, a firm "no!" and ignoring them for a while should get the message across. Remember to shower Bobi with lots of love and attention, good luck!