Hi, Teresa. Although I now live in Florida, we lived in Utah for 21 years while our kids were growing up and they still live there, so I visit very often, and plant their gardens for them.
Hostas do grow wonderfully, but yes, they need regular water through the summer months because it is SO dry.
The Hosta House nursery in Salt Lake City, up on the east bench is a real treat to visit, so if you go to visit your daughter, be sure to make a little trip there! But, all the good nurseries carry nice hostas.