Waking 9 week old to eat?

M

Ok ladies my little one is 9 weeks old she has doubled her birth weight. Her doctor says wale every 5 hours at night to eat but then I hear people say no way let them sleep they will wake when hungry. My cousin is a pedi nurse said the same thing. What are you ladies doing? I’d love to let her sleep u til she wakes up. This week I wouldn’t cause her eating has been awful thanks to what I believe is a leap week. She only ate 20 ounces in 24 hours 😭 but tomorrow is a new day hoping it gets better. Shots and leap week at once was a no go!