In my experience the sizing varies but the sizing guidance on the item/in reviews is very accurate.

Yes, please tell her to read the reviews. I bought a pair of kick-flair leggings (butt-boosting too 😊) about a year ago and most reviews said ran small, to consider ordering up a size. With some hesitancy, I did and was glad. Those pants are like wiggling into a girdle - but once on, completely comfortable and look great.

Thanks, I’ll pass along the advice.