paying off credit cards by getting an equiity line on mortgage

My 59-year-old sister has $10,00 in credit card debt and some cards have interest over 20%. My mother and I payed them off a few years ago but they have been used again so we're in this situation for the second time. My sister is unable to fully support herself and has used her credit cards to live on. My 80-year-old mother is looking into getting an equity line using her home (payed for) as collateral. The bank wants her payroll check stubs, last years W-2's, copies of flood and homeowners insurance, a copy of her deed, an attorney's letter of opinion (since her home is in trust), etc. I would like to see my sister call the credit card companies and try to renegotiate her interest rates as a first step before our Mother risks putting her home in jeopardy. While Mother is able to work right now, the possiblility always exists that something could happen and she would not be able to make the payments. She has already compromised her financial security by depleting her savings account by helping family members and I feel having a lien against her home is illogical and risky. Am I overreacting and being overly protective? Could you please advise us? Thank you.