How long should my 10 week old baby nap for?

My baby girl was born 8 weeks premature. She’s currently 10 weeks old and now sleeps for 3-4hrs through the day at her nap times. And at night she’ll sleep anywhere between 3-5hrs. Is it normal for her to sleep a lot through the day? Throughout the day when she wakes up from her naps she’ll cry and fuss, we let her fuss for a few minutes then we’ll change her, talk to her and then feed her. After feedings she’ll usually fall back to sleep after about an hr of being awake. And repeat!

Should she be eating at specific times or can she eat whenever she wants? And is she sleeping too much during the day?