My DS started his one nap a day all by himself and it literally happened overnight. However he got a cold the other week and his routine went a bit to pot and now he is a little monster again. He was having one nap at 11 or 11.30 and was sleeping for a good 2hrs but recently he has been going down for a nap at 10.30 and i can't extend at mo cause he will get OT and we are back to square one. I am trying to get him to have a 20-30min nap at 2-2.30 but i never let him sleep past 3 as he won't be tired enough for bed at 7ish. Hopefully it will sort itself out again, but i do wish i would hurry up ha ha
I'm sure your little one will be ok for the christening, my son was 6months old on his and he was fine although a little ratty near bedtime but the stimulation of everyone coo'ing over him kept him going. good luck with it tho.
x