I've spent the last few days searching through baptism records trying sort out mystery of the missing siblings. I found out that the information I had before wasn't quite correct anyway, and so the order in which I had had them being born wasn't right. Here is what I have found to be correct; all backed up by baptism records so far.
Ada Elizabeth: Born 1904; Baptised 1904
Florence Ethel: Born 1905; Baptised 1905
John Austin: Born 1907; Baptised 1911
Leonard James: Born 1909; Baptised 1911
Laurie Belle: Born 1911; Baptised 1911
Belle May: Born 1913; Baptised 1913
It seems strange to me that all for the girls were baptised within a year of their birth, but the two boys waited 4 and 2 years respectively. It isn't something that I will ever be able to find out why, but it is intriguing nevertheless.
I have birth records for a Leslie Edge born in 1920 and a Joan Edge born in 1923. Leslie was born in Chatham the same as the previous children but there is no record of his baptism in the area. Joan however was born in Farnham, Surrey. This leads me to believe that they had moved before that had him baptised. To check the baptism records for the last two I would have to travel to the parish archives, and with not being able to drive, having a one year old son and being 32 weeks pregnant, I don't think it is likely that I am going to get there any time soon! Surrey say that are putting the archives online in 2013 so this might be one to put on the end of a long to-do list.