i have a smorph, it fits on my chicco trio 4 me just fine. my 2.5 year old goes in it, expecting out new baby in july, and his sister (will be 2 then) will be going in it and he will be walking. not brill for LONG journeys cos they cant sleep in it really, no support. but i just switch my 2 round as they are old enough. i would say make sure u carry a sling just in case your DC1 needs a nap whilst out. then u can fold the smorph up and put him/her in the pushchair.