I used the Ergo to carry dd on my back until she was 2.5 - I forget how much she weighed, but she was in the 50th percentile. I stopped because I was a few months pregnant, but when she got jealous of me carrying ds after he was born I wore her for a 15 minute walk when she was 3.5. I couldn't do it all the time, but it wasn't unbearable.
Re: Big Kids?