First of all, Welcome to YT!!!!!
I agree with Snowa. It sounds like your little girl is eating just fine. These guys really don't eat very much especially at only 3 months old. Mine one is 9 months old and still does not eat very much but he is healthy and at a very healthy weight, so he is getting enough food. Try to stick with one puppy food. Changing food frequently will cause them to be picky eaters and may upset their stomach. You can also try hand feeding her the kibble, alot of them will eat it alot better if you hand feed them. But then they will probably expect it all the time.
Congrats and Good Luck with your little girl!!!