Bras for morbidly obese 80yo with underbreast sores

We’ve got an elderly family member who weighs about 300lb. She has big old boobs and doesn’t wear a bra. She’s started to get sores under her breasts. Her doctor has said that she needs to start wearing a bra but she doesn’t want to be uncomfortable and wouldn’t be able to put on like a sports bra over here head. We honestly don’t know wear to start. Anyone have any experience with this or anything similar?