Clothing for elderly that make is easy for them to change their diapers?

My aunts are 90 and 92 years old. They’re used to wearing pants, capris, and shorts. However, it’s increasingly difficult for them to get the bottoms off and on. Most of the time they spend wearing their robes or robe like pajamas.They need some clothes that they can wear outside of the house such as doctors visits and also around the house for when the therapist and nurses come. . . And basically, just to feel good about themselves. Does any one have a suggestion for a company online? I’m looking for comfortable dresses that they can wear. Nothing fancy, just cotton pullover‘s or button downs, zippers, or snaps. They each have a caregiver that comes to the house that can help them with dressing.
One has gained weight and went up two sizes. The other has lost weight and went down a size or two and nothing fits and the things that do fit are only the robes and pajamas.