These dolls are called, "PK". I don't know anything about them, other than that. They were first released in 1990.
The one on the left is named Krissy, but I renamed her Sam, and I got her in 2004.
The brunette one is named Laura, but I renamed her Lucy Poosy, and I got her when i was either 2 or 3. (Hey, I was young!) So that would probably be 1998 or something.
Lucy came with a playground set, and they all can attach onto things. I only know that they are called "PK", but that's all. I'm not even 100% sure.
In this pic, I remember when I first found the bald spot. I got a pen and drew stitches. LOL. I was young, once again.
Anyhow, if you have any information, please reply! :D