we did use stair gates with ds but i can't remember exactly when he was totally ok with them. i only remember it was well before 22mo because at 22mo he had learnt the knack of coming down 2 flights of stairs when he woke up at night in his sleeping bag
needless to say we got rid of the sleeping bag promptly then!
dd is 18mo and i'm starting to let her go up and down sometimes on her own without supervision, but i don't know if thats too soon and whether i should be cautious for a bit longer. she is pretty good at the stairs. i know no one on here can tell me whether she's ok unsupervised, i know that's a call i've got to make myself, but just looking for a general picture
thanks!