Welcome to the Forum, and welcome to Holly! She looks like a sweetie.
First of all, tell us what she is eating. The kind of food you're feeding makes a difference in the amount. High quality premium foods require less than supermarket foods. So the amount depends on the brand. It also makes a difference if she's eating puppy food, which she should be at this age.
That said, we usually feed puppies three times a day until they're six months old. They get about 1/2 cup at each feeding, again depending on the food. Has Holly seen your vet yet? The vet can tell you whether her weight is on track and how much food she should get. But I'd be feeding her three times a day.
Hope that helps!