What should be new born feeding hours at six week?

My baby girl born on 75th percentile & was taking milk every three hours in 24 hours but from last two nights she is taking 6 to 7 hours sleep, & she suck only five minutes on breast after this long sleep then again she is taking 3 hours sleep,is it normal or should i awake him for feed after three hours,I am mostly breast feeding with one or two bottles in a day,