My other half has always bought her hold ups from a well known Pri***k high street fashion store.
She is 5,8 and always buys medium. But they always start to fall down hee hee, after walking a short distance.
She had some on recently, we had only walked a few hundred yards and they started to come down. Got some strange looks off drivers, as she proceeded to take them off in the middle of a busy street hee hee.
She will try the small size, but she would like comments off ladies as to why this happens.
She has stopped using creams on her legs as someone suggested this was a cause.
Been there and it is not a good experience. Get a good make and ones that are lon enough. Also care when putting on that top flat against skin. Lacy tops with broad band seem more reliable.