Hello, and welcome!
Congratulations on your new furry addition! : )
She will need time to get used to her new surroundings, but 2 months sounds like an adequate amount of time. I'm assuming she comes out of her carrier to eat, drink, and use the litterbox and you did mention that she roams around, so what you have to concentrate on, is increasing her 'roaming' time and decrease her carrier time. She's returning to her carrier because it's a small, tight place where she feels most secure.
In order to encourage her to come out more often, it would be a good idea to enrich her environment. You can do this with a tall cat tree or kitty condo which has different levels, shelves, and 'hidey' holes. Cats love to be up high and she will feel safe up on the top platform of the structure. Also, she needs great toys that will interest her and that she can play with by herself, in addition to interactive toys she can play with, with you. Here is a wonderful list of toys and even a dvd she will love:
You can also get some Feliway diffusers. These emit cat calming pheromones and are great for introducing new kittens to the household. http://www.feliway.com/us
She just may be naturally shy; if she doesn't like to be held or held for too long, respect her wishes. Some cats don't like to be held at all, because they feel insecure and may panic if all four paws are not on the ground.
In addition to the carrier, try to substitute other items, like a cozy cat bed, for example, so she has a choice of where to sleep and/or feel secure. You can lightly spray Feliway in a new cat bed and on the cat tree/kitty condo to make her feel they are 'familiar' to her. One note: wait until the spray is completely dry (about 20-30 minutes) until allowing her access to them. You can find Feliway spray and plug ins at major pet supply stores or order online.
When you try to engage her outside of the carrier, do things gradually, move slowly, speak to her in a gentle voice and repeat her name frequently. Try to get her into a routine, where she knows, this is eating time, this is playtime, this is sleeping time, and that might help her feel more secure, too.
I hope things work out well with your new furry girl and please let
me know how things are coming along.