The GAP jeans are all usually very long and sometimes come in lengths (like tall) :)
Target has maternity pants that you can buy in reg, tall or short. I don't think all of there pants can be order that way, but at least some and there are often more on their website than in the store. also I am 5'7" as well and i have bought a couple of pairs from motherhood maternity and they were plenty long enough, if you can just try them on to make sure, if not a lot of them run long!
I think old navy has differnt length pants as well. I love their maternity pants.
I believe motherhood maternity (motherhood.com) caters to tall women. I have the opposite problem,I am only 4 10 even petites are too long.
Nope, sorry. I buy my maternity clothes at the thrift stores.