@FearlessDiva,
In the end you need to pick a name that you both like as someone is going to pick apart whatever name you choose.
As someone else suggested you do need to remember this name will be used into adulthood so be careful in that respect .... I also know of people who went into adulthood and even younger using their middle name because their first name was not really appropriate or just did not fit them.
The one thing to think about using the word doll as part of her name is as a woman doll is often used in a condensing way toward a woman. The one thing is if she doesn't like it as an adult she found keep Rosy and drop the Doll.