My 3 week (4 weeks in 3 days) old baby has now been asleep for 5.5 hours. The midwives said no longer than 6 hours but was that just in the first few days? Should I wake her at 6 hours for a feed? She is breastfed so this is new territory for me as my son would NEVER go this long!! She is gaining weight really well; 13oz a week and was 7lb 9 when born and 8lb 13 last Tuesday. Thanks!