Here's proof that a 36 inch 34 lb child can still be easily carried around in a sling. A sling, by the way, that I made myself (from a pattern from Elizabeth Lee Designs). It's the Classic Sling pattern and I follow the instructions with the exception that I leave out all the padding 'cause it's too bulky and hot for Texas.
When he was first born I carried him in a plum colored fleece sling that I made from the same pattern.
That spring I switched to a lovely floral material that we used until he was 1.
Actually, just last month I carried 46 lb 48 " Giselle around in the striped sling while at HEB - no picture of that.