transitioning nipple sizes

we use the avent bottles for my daughter and we just bumped her up to 3.5oz and she feeds every 3 hours, she's 1 month old she were using the #1 nipples right now and we wanna try switching her to the #2 nipples...is this too soon? on the package it says 1m+ but i'm just wondering if the flow is faster or does it depend on how hard they suck? do these nipples require harder sucking for the milk to come out?