I want to buy my mothers house?

My mother has a house on a mortgage the house is worth �120,000 and the mortgage outstanding is �40,000. could i take an intrest only mortgage out for �60,000 costing around �200 PCM against that house so that my mum can use this money to pay off her mortgage then give me �20,000. This will allow my mother to retire and provide her security for the rest of her life and inturn secure my inhertance??