Definitely not PJ, but a button down nice nightgown that is washable would be a good idea. Easy to get on and off, and she might actually wear it once she is healed.

https://www.ralphlauren.com/women-clothing-sleepwear/jersey-sleep-shirt/100045303.html?cgid=women-clothing-sleepwear#start=1&cgid=women-clothing-sleepwear