Amount of bottles at 11 weeks!?

How many ounces is everyone else’s 11 week old taking? Penelope will be 12 weeks old Saturday and she’s still only taking 3 ounces at a time occasionally more depending on her mood. She’s gaining weight fine, she was 5lbs 3oz at birth (2nd percentile) and is now 9 1/2 pounds (6th percentile according to Glow Baby, 10th from her pediatrician) but I’m concerned that she’s not eating enough. I wasn’t able to go to her appointment on the 6th because I couldn’t get out of work, so I wasn’t able to bring it up. Just curious if this could be normal, her brother was downing 8 oz bottles at this point at that age but he was also 8 pounds at birth so maybe it has something to do with her being so tiny and the growth restriction?