Ashton's mum - actually, you are doing the right thing by first extending to 3.5 hours then on to 4 hours. In her book Tracy actually recommends increasing the time over about a week long period, first by an xtra 15 mins for about 3 days (ie 3h15 between feeds), then .5 hour (ie 3h30 between feeds) for 3 days, then the full 1 hour (4h between feeds) after that. So easing into it is the best and kindest way.