I want to purchase this for someone who just had a baby bc we live up north and these are super handy for when you have to go out in the cold. The thing is, her baby is only 4 lbs right now. If I buy the 0-3 mths do you think it would still be waaaayyy too big or do you think it would be fine by the time winter comes? I had big 9 lb babies so I know nothing about no 4 lb peanut! Lol