Great question!

This is a great chart to explain what a F2 dog is:

Mishael (Momma) is a mixed breed dog. Her parents are a Golden Retriever Mom and a Toy Poodle Dad, as shown in the top row with the 2 dogs. Their offspring makes what is called an F1 Goldendoodle, which would be 50% Golden Retriever and 50% Poodle; as shown with the first dog in row 2 of the picture. Since the Dad was a Toy Poodle, it makes her a F1 Miniature (or Mini) Goldendoodle. She is much smaller than a Standard Poodle. The same thing for Daniel, his Mom was a Golden Retriever and a Toy Poodle Dad.

Mishael and Daniel bred, so if you look at the second row of dogs in the chart, ignore the 3rd dog in this row and look at the 1st and 2nd dogs. Mishael would be the first dog, bred with Daniel the second dog, so a Mini Goldendoodle with a Mini Goldendoodle. Their offspring would be in the third row, this time ignore the second dog in that row and look at the 1st dog, they would make a F2 Goldendoodle. This makes them 50% Mini Goldendoodle from each parent.

Mishael is 20 lbs and Daniel is 25 lbs. We expect their puppies to be 20-25 lb range fully grown. The boys usually being a bit bigger, and the females usually on the smaller side. However, there is no guarantee that they will be this size. With a healthy diet, the puppies could range from as small as the Mommy to as big as the Daddy. There is a small chance that they could be as big as a Golden Retriever since it is in the bloodline, and it depends on which genes the puppies pull from, but it is not as likely. They will also be more hypoallergenic than a Golden Retriever, since they still have 50% poodle in their blood.