I think it would be good if the person you are helping ordered the marriage cert for Frances Dorothy's marriage in 1940. In these types of searches, you need every bit of help you can get! Confirming what she reported for her father's details on the registration may help.
You mention that that Charles Kemp is possibly seen to be the person that took care of Frances Dorothy in her early years?
From jc26red's details on the Kemp family in the Glasgow area, this I think is them from the 1911 index, all under the ref of 644/5 16/ 17 - Garngadhill, Lanark.
Charles 40
Mary 38
Peter 16
Mary 14
Eliza 8
Charlotte 7
Catherine 4
Peter 69
John 32
Monica
Added: Baby Charles who showed in 1901 died that same year.