Kabed es Avicha Ves Imecha
“es” expands the concept to include more- Chazal teach us it includes a parent’s spouse (i.e. step parent) and older siblings. I don’t know any source that says that it includes other relatives. Respecting an aunt would be like any other older person who deserves respect, especially if elderly. Honoring mother would trump honoring your aunt, unless it means doing something against halacha.
