Renewing Minor's pport?

ok so my father is trying to renew my little sisters pport that expires in a month. Because she is a minor, she needs both parents to be present to renew it or if one parent is present, the other must agree to sign a authorization form in front of a notarized person. The problem is my mom, who is extremely bipolar, refuses to sign this form. She refuses to leave the house and because of this we can't take this route either. I was told if we brought a doctor's note stating her mental condition, we would be approved for my sisters pport renewal. The problem is my mom refuses to leave the house and the doctor wants to see her in person in order to get the letter. I was wondering if there is any other possible way to renew my sister's pport. This is an emergency because we need to renew it now~!!! 10 points to anyone with helpful answer!