Yep I should imagine 42 flannel would be enough! I think I have about 20 flannel, 20 terry. Make sure you now start stocking up on plastic pilchers (get a few packets and start stocking up on different sizes) they can be quite hard to find sometimes too. I suggest the ones from Big W, they seem to be a softer plastic. Are you planning on using nappy pins or snappies? I found I had to shop around to get the best pin too!