I know newborns feeding can be all over the place, but i am getting a bit flustered over my newborns feeding , she is a week old and seems to want to feed all the time , it was every 2 hours or so now its more often sometimes she has a feed then wants one 30 mins later etc.Is this ok?

I dont think she is feeding the whole time on there as she falls asleep or relaxes then starts up again.

Is it ok to feed them as much and as often as they want on the breast?
Also

she is getting frustrated from my milk supply, i know that the breast is never empty and it isnt as i hand express it to check and milk comes out but when they are emptier she doesnt like it and cries and pulls on and off ,i am worried she isnt getting enough?

Thanks all