Hello and welcome to the forums,
Cody and FaeryBee have given great advice and resources. I agree that your little girl should see an avian vet right away, since if it is egg binding, it may be lethal.
Meanwhile, you've come to a great place to learn even more about the best of budgie care practices.
Be sure to read through the forums, including the links provided above, to ensure you're up to date on everything. If you have any questions after doing so, please be sure to ask as we'd love to help!
Hope to see you around!