My son has his PhD graduation ceremony soon at the Albert Hall and I need help with finding something to wear. I am in my 60’s, 5’2” and a size 16. I retired a couple of years ago and live in jeans as I spend my time walking the dogs and gardening. Also, I also have a dodgy hip so usually wear trainers but I can wear shoes but only pretty flat ones. I don’t want to spend a fortune as I’ll probably never wear the outfit again. Any advice please?