Can I sign for a mortgage loan if Im a durable power of attorney.

Hi, Im my moms fulltime caregiver, and her durable power of attorney, and have been for many years. Were in the process of selling our house in the next few months. We both own the home, both of our names our on the title, as well as both of our names on the mortgage. When we purchase a new home, and apply for a new home loan, can I sign for her? Thank You!