Hopefully you told hte manager on duty about the injury and that person made an incident report. If so, then you may no thve to file suit, as they will likely reimburse you for yrou daughter's medical bills. If they will nto voluntarily pay, then you may hve to fiel suit. If you did not timely report the injury to the manger, you may have a hard time proving your case. If htey will not pay, you should consult personally with an attorney in your area. Many offer a free or low cost initial consultation.
Good luck
