My advice...don't worry about schedules at one week old. Her metabolism is fast and she was used to "eating" on demand for nearly a year inside of you.

I'm not really familiar with formula feeding issues, but FOR SURE you breastfeed on demand at this age. It will not create bad habits later...it's just too early for that.
Also, you compare your 2 children's amounts...I wonder if boy vs girl might mean differences? All babies are different anyway. AND, if you do the math of the total amount of oz they eat in a day, isn't it close to the same? 3 oz every 2 hrs vs. 2.5 oz every 3 hours?? For a 12 hour period the 1st amount would be 18 oz and the 2nd amount would be 10 oz.