A family mystery

This evening I have been surfing the net and specifically the Find My Past website, looking up my Mum's side of the family, and she learnt a few things she never knew for instance her Grandmother on her father's side, name was Emma, and although that was interesting it's her Mother's side of the family that has always been the mystery, her Grandmother never married and although we know her name, the name of 2 of her sisters and where she was born, we really didn't know anything else, today we found a record in the 1911 census for her family, the Dadleys in Daventry as  we expected however the census threw up 2 further mysteries, firstly there is nowhere on the census someone named Florence Margaret Dadley, not anywhere, now Florence was born in 1888 and had her daughter (my Mother's mother)  in 1919, but there is no record at all for her in 1911!

The second mystery is the discovery of another sister, who has never been mentioned at all, a Clarice Victoria Dadley, born in 1898. Now I  have found a marriage record for her in 1924, but being broke as usual I don't have the money to pay on the site to look to see who she married and when she died or if she had any children!

In order to check that this is the right Dadley family (and I am sure it is) we have ordered Florence's birth certificate from the General Register Office now we just have to wait for it to arrive (which won't be til after the 26th November and it will be quite easy to check as the Father of the Daventry Dadley's in the 1911 Census had a very unusual name Desmora Lennox Dadley. The sad thing is that Desmora died in 1945, 1 year after my mother was born, he never knew his granddaughter Muriel, let alone that for a year he had a great granddaughter as well.

But the thing I want to know it

• Where was Florence in 1911 - why doesn't she show on the Census
• Who was Clarice Victoria Dadley? And why wasn't she ever mentioned?

Enquiring minds need a Time Machine!!!!