I have a 3 month old named Jinxy. He also cried a lot when we brougt him home about 3 weeks ago. I read about it in a cat book I got that said that they are scared to be in a new environment and perhaps without their brothers and sisters for the first time. They are confused and need to be held a lot at first. They do not like to be alone, so you should try to carry her around a lot at first to let her know you are the mommy and that you will be there for her. After a while, it will get less and less.
Junxy still cries if left alone in a room a little, or if I am playing with him downstairs and I go upstairs, he cries. At first it was because he did not know how to get where I was because he was not familiar with his surroundings, but now it is because he wants me to stay with him where ever he is at the time and play with him. When I leave, he cries like a baby. I just call him and in a minute he will come running to me.
In other words, it's normal. Just give her lots of love and attention.