Dolly is the only female puppy from Beethoven 2nd.
Dolly is first seen with her mother Missy aswell her siblings, Who Missy is later taken by her evil Owner Regina.
Ted and Emily take the puppies after the event happened between Regina and Missy.
Ted and Emily distract the dad ( George ) and take the puppies to the basement.
Emily and Ted later tell their older sister Ryce to come down quitely to the basement, she follows.
She is then delighted by the 4 puppies, Ted tells Ryce that their dad and mother don't know yet.
They later convince their dad to let them keep the puppies until bigger and older.
The Kids ( Ryce, Ted , Emily ) head to the park to name them.
Dolly was going to be called "Morgan" but Emily later says she "Looks more like a Dolly".
Thats where she became a part of the Newtons family.