There are many choices of bath benches and shower chairs available. They are sturdy and lightweight allowing easier transfers for all size people. The ability to sit in the bath or shower allows for safety, comfort and more independence. Scroll through the many types and find the best one for your individual needs.
A Transfer Bench straddles the side of the bathtub,
allowing you to sit down outside the tub and then
move over the surface of the bench into the bathtub.
You may also want to consider installing grab bars
on the walls of the shower/tub area.