She’s 90. She can wear whatever she feels comfortable in.

Tshirt, Bikini, burkini, birthday suit

Based on my trips to the local nude beach she’s a ‘hot babe’ with her figure

Lands End used to have a good variety.

tlcdirect.org is related to the American Cancer Society. I have purchased other products from them they are good quality. I think they also have prostheses that are better for a swimsuit. I just use an old one since I do not go in the water often.

Some regular bras and swimsuits have pockets to adjust size and for more or less coverage, one of them might work.

Hope she finds something that "suits her".

Tell her I understand...