Enduring powers of attorney (EPAs) were replaced by lasting powers of attorney (LPAs) from October 2007. EPAs made before that are still valid and you do not have to convert them to an LPA unless you want to.
One issue with EPAs is that they give your attorney power to deal with your property and finances for you, but not your health or welfare — for example, where you live or your medical treatment and care. You can make both a property and financial affairs LPA and a health and welfare LPA.
So your mother could decide to keep her existing enduring power of attorney (because it already gives her attorney the powers they need to deal with property and finances) but make a health and welfare LPA too. Or she could cancel her existing EPA and make two new lasting powers of attorney — one covering health and welfare, and one covering property and finance.
Whatever she decides to do, a solicitor can help with the whole process.