DD (now 13) slept in her pram outside our kitchen door until she was 18 months. She was an early waker (05.45 ish) and by 9.15/30 she was was ready for a sleep, this was when she was say 6 months.
I'd literally put her in the pram, get my keys, go out the front door, down the side if the house, along the back passage and in the back gate.
I'd push the pram to and fro for 5 minutes and hey presto....she'd be asleep.
I'd leave her on the patio until gone 11am fast asleep and pretty much get everything done.
I put this down to a few things.....
A) luck
B) her dummy 😊
C) the fresh air
and D, she had an old fashioned second hand navy silver cross monster of a pram (we loaned from a friend for a year) she loved it, she always slept well in it.
She was out in all weathers except pouring rain.