Not waking to eat

My baby is almost 3 weeks old she sleeps super good , In the beginning at the hospital they told me to wake her up every 2-4 hours to feed her , she was born smaller weighing 6 pounds but at her 2 week appointment she went over her birth weight ,weighing 7.11 they never told me weather to stop or keep waking her for feedings , we’ll it’s currently 4am and she won’t wake to eat , the last time she ate was 10:30 until about 11pm. I’ve dive everything to try to wake her but she’s out cold , a diaper change didn’t even wake her completely, do I just let her sleep? She’s sleep all night if I never wake her to eat but tonight she’s not wanting to wake up and stay up , she latched for 5 min on one side and 2 min on the left before going back to bed .