The dolls you have are modern dolls (no older than the 1970's) which were inexpensive and mass-produced (in Taiwan, Korea, China). They would have come in a box with a wrist tag which would identify the manufacturer's name. They are the kind of doll that can be purchased at Walmart, etc. for abt. $10. There is not a market for them with collectors (but any doll, given enough time, willl be collectible). Since your grandmother gave them to you, you may wish to keep them for sentimental reasons, perhaps to pass on to someone else in your family.