Hi Claire!
Good idea for her to post here, as I would think that some of us have some garments and accessories if that is what she is needing. I have hosiery and gloves by Mr. John, maybe a few other smalls, but no actual garments such as a dress, blouse etc. I have a friend who is a serious collector and has a lot of Mr. John's archival stuff from after the salon closed, and I could possibly ask and see if she can be of some help.
If she needs any information or photos of his early work with hats, I am happy to help.
Have a warm and healthy holiday.
Regards, B