When ds was younger he wouldn't sleep in the carseat in the pushchair either because he was always watching me and trying to catch my eye.  Had to pull the hood right down so he couldn't see me if I wanted him to go off to sleep.  x

I have to cover LO puschiar with a blanket too as is sooo nosey doesnt want to miss a thing and it works 90% of the time. I also have a little sheep that makes noises like ocean/rain/stream etc and that blocks out the noise stimulation too.

if she's used to lying flat for naps now maybe she doesn't want to be halfway sat up as in a carseat? Also could be that she's paying too much attention to what's going on, my son would only nap in buggy at this age but was getting harder to get him off to sleep and I started covering pram/pushchair with a sheet (could use cotsheet folded or muslin or blanket) so he couldn't see out (was really hot summer too so gave bit of protection from sun though stll creamed him lol). Got the mick taken out of me for a bit by a friend but then she noticed lots of other people doing the same thing!!

Don't have same problem with Esther cos if out with buggy she's almost always in sling and she mostly sleeps in there 9tho if not tired started protesting for a bit or nosing first)