also Lord & Taylor and JC Penney.
I've found that some of the stores taylor listed (Jcrew, Old Navy, and Express) do not carry petites in stores near me, but that may vary by location.
I'm a petite too, and the most important advice I'd offer is to repeat what Angie said about online ordering (and returning when things don't work out). It can be daunting and time consuming but if you aren't ok with online shopping your choices in stores will be EXTREMELY limited, and shrinking every day. For example, in just the past year, the two Nordstrom stores I go to in the greater Boston area have stopped carrying ANY petites except things that were returned. Nordstrom has a great selection of petite sizes online.
Also you may want to check out extrapetite.com. She's about the same size as you and gives a lot of details about what sizes work for her, including measurements of herself AND the garments. Her style may not be your thing, but she's a fabulous resource. She also occasionally orders from places that cater to the Asian market (as mentioned by kkards), and she reports on how long they took to deliver, how well they handled returns etc.