No. But your sister’s account could be subject to claim if you were ever to run into financial difficulties. In a bankruptcy proceeding or divorce, her account may come into play even if you argue the funds are not yours and your name was placed on it for estate planning purposes.
Harry S. Margolis practices elder law, estate, and special needs planning in Boston and Wellesley, Massachusetts. He is the founder of ElderLawAnswers.com and answers consumer questions about estate planning issues here and at AskHarry.info.