Not had time to look properly, but I did find that on the 1911 census, Margaret gives the fact that they have had 8 children, with 6 still alive. All the children that you mention are there, but also AGNES, born 1902.
I found that John was married to Mary Alice Horrocks in Salford, So I don't think that his Family would have been in Orrell, Upholland Or Ince. I will have to check the rest when I have more time. It may be a good idea if I checked William and Margarets Brothers and Sisters as well, as they were all born around Upholland.