SOS!! Medical bills and green card application

Hi my kind/smart friends: I submitted my I-140 last Nov. My mom came to visit me and I am her sponsor. She doesn't have insurance here but had to go to the emergency room a month ago. Now bills are coming with thousands of $. My mom signed all the documents in the hospital. The hospital told me we could apply for the charity financial help, and they would send the application to the embassy (I don't know which embassy they were talking about) to see if she promised not to use USA resources. Is it possible that they will go through such a progrss, or they just want to give us pressure in order to get bills paid? I am wondering how that process would affect my green card applicaiton. Should I responsible for my mom's bills since I am her sponsor? Someone suggested me not to respond to the hospital at all, but I don't think this is good, even from the point that we are Chinese. What is a better way to deal with the bills? Thanks a lot for any suggestions in advance!!!!