I am of no way any help but a funny thing came to mind! Everytime Im out shopping and I accidently wonder into the petite section, as soon as I realize I try and walk out ASAP as I dont want someone to think Im all trying to act like Im petite or something!!!! (Im a size 10!!) I WISH I could shop in the petites!!! Good luck!! I saw LOTS AND LOTS of 0 in Banana republic!!
Petite isn't about size but rather proportions. The petite section will have all of the regular sizes. There are even plus petites.
Those of us who are petite can be skinny or heavy. What makes us petite is that our bone structure is smaller, e.g. the length between our shoulder and our wrist is a few inches shorter than a "normal" woman's.
Generally speaking petite sizes are for women who are 5'4'' (used to be 5'3'') or under. Also there are some women who are petite on top but regular sizes on the bottom.
IMHO petite sizes would be more available if more women knew that they were petites but unfortunately a lot of women are under the impression that petites are only size 0's. That's not to say that the petite section at stores like BR aren't full of size 0's or now 00's but that's only because the size 8's and 10's sell out first because there are a lot of more of us than there are size 0's (at least that's my theory).