OP here- She tried the Vera Wang's and they were way too big. The extra small at victoria secret fit well, although I will not put them in the dryer. We bought one pair for $40 and will see how they work out before buying more. Did anyone have VS yoga pants they didn't like?
Old Navy is great for yoga pants, I bought a pair last spring and I love them. I also have a pair from Target (Champion brand) and a week ago I bought a pair from Marshall's for 14.99. I've only worn them to work out in once so far but they seem to fit well.
Victoria's Secret's Pink ULTIMATE yoga pants/leggings are awesome no worries about see through pants and many of them are reversible. Their regular yoga pants aren't so great... It has to be Ultimate.