I don't think many babies are the size she is, I would guess she's on the 99.6th centile for weight which which would put her in the top 0.4 % so out of 1000 babies she would be 1 of the 4 heaviest. For context according to tge WHO weight charts at her age anything above 12kg would put her at the very top of the graph. The weight range for those size 8 pull ups is 18kg+. Whilst the weights are only a guideline and not exact that's a big jump from 12 to 18kg so either Shannon is putting her in nappies far too big or she is exceptionally heavy for her age, like off the chart heavy.