6 week old baby - should I wake her to feed in night?

Hi all,

My 6 week old baby is healthy, exclusively breast fed and putting on weight - so all good.

On the sleeping front she is starting to sleep longer YAY - but my question is she makes a lot of noise in the night (has) groans and other noises and I also hear her making rooting noises (hunger) but she is still fast asleep.

As she is starting to sleep longer at nights 3- 4/5 hours and I know she is learning to join her sleep cycles. The question is should I let her sleep until she wakes up crying from the hunger because she needs to know how long she can sleep with the food in her tummy? Or should I wake her up as I can hear that she is hungry from he rooting noises?

Thanks for your advice