More milk please!

✨JBR✨ • Married for two years. Nanny. We're expecting our first baby in March!
My daughter is 2weeks old and was born at 34weeks. 
She's breastfed with formula to supplement. I fed her 2oz and then 1 hour later she wanted more, so we gave her 2 more oz. How do I know when to increase her feedings? Should I talk to her doctor?