I eat when I am hungry, not when the clock tells me so I wouldn't expect my children to. It is actually better for them to set their own feeding pattern, they learn to control their appetite. If your HV knew anything about breastfeeding she would kow that it is harmful on your milk supply to impose a routine on breastfeeding babies, and that it is normal for a breastfed baby to put on a load of weight at the beginning, this tends to slow down as the baby gets older. I personally would not listen to a word your HV says and speak to someone who knows something about breastfeeding like a peer support counseller. Cally piledon the weight, she jumped from 50th centile at birth to the 98th at one point but has settled on the 91st and is no way fat. She sets the pace for her feeding, and you will find that after a while they kinda get their own loose routine where they bfeed for shorter periods which are spaced out more.