As Lymorelynn says, I am surprised that you have been able to persuade such a young baby to eat solid foods. However, if she is now eating solids, then please carry on giving her as much as she wants.
Kittens are not usually fully weaned until they are over six weeks old, in my own experience. They will be learning all sorts of things up to that age from their mother which is why others have commented about it being so unnatural to remove a baby from its mother so early. You probably were not aware of this but the breeder who let you have this kitten ought to be advised if they don't already know.
Try to get hold of some of this:
Cimicat. If she will lap it up, that's a good sign. You can give her this in addition to the food provided on a separate dish.
My queens usually have their babies suckling still until they are well over four weeks old and they will be just beginning to lap when they are over five weeks. I hope you will have joy and success with that tiny kitten. Please let us know how you get on.
