Hi wendi, when you ask what clothes, can you be more specific? What do you mean sissy baby, it can mean different things to different people. What age are you talking about,
infant baby, toddler, little girl? Infant babies wear items more suited to be pretty and cover and just keep babies warm, walking or crawling is not part of the design in these clothes. Then there are infant clothes for the crawling stage, these are shorter to allow for that. Then there's the toddler stage, more suited for the walking baby. And just about anything goes here, same for a little girl.
If you want to have a look at some sites that sell sissy baby stuff, here are some for you. These days there are allot of sites to check out.
http://www.sew-creations.com/
http://prettydresses.homestead.com/
http://www.ldfashions.com/
http://www.leannesprettydresses.com/index.html
http://www.bigbabyfashions.com/default.php
http://www.cutestoneofall.com/index.htm
http://www.foreverakid.com/
http://www.laceys.ca/default.asp
http://www.rufflesnlace.shoppingcartsplus.com/RufflesNLace_home.html
http://www.fwdsites.com/catalog/Stores_App/store.asp?Shopper_id=11625852006222227531162&Store_ID=585&affid=1000&langid=en_us&page_id=19
http://cindiescreations.com:4180/CD.Creations/
The site below is a site that sells real baby clothes, but is a great spot to check out things you may want to use as a model, for items you might want to have made by some of the custom adult baby clothes makers at some of the site listed above.
http://www.bestdressedchild.com/
I hope this helps you out, and if you have any other questions, fire away! Have fun.
Luvs It.