It sounds ok as long as LO is peeing, pooping, and gaining weight well. It's on the end of the spectrum for sure, but both my LOs have done huge stretches overnight from being very young (DS first did 12h straight at 8 weeks and had done the equivalent of 10-5.30 from maybe 3 weeks or so, DD was similar). Every Mum is different in her capacity to produce and store milk (and calories) and every LO is different in what they can take at each feed. Whilst I think the guidance is for 8-12 BFs per 24h in the early days, in reality I think we did 9 maybe once, 7-8 for a week or two, maybe three, and then 6 or even 5 has been our norm. I think as long as she is following her LOs cues, not holding her out for a feed, and LO is thriving its probably fine. Just tell her to wait for the growth spurts - didn't know what had hit us at 11 weeks!!