Sorry to say, no progress.
Do you have the daughters' marriage certs? Just wondered if there was anything else on them - father's name. witness names etc that might help?
I am wondering if MILES was another married name? Or maybe mistranscribed for MILLS?
You may have to ask for a BVRI look up. Or have you tried the IGI for the family?
Arranroots

One thing - probably a red herring - I noticed that in 1901 William is described as an army pensioner. In an earlier census (forget now which one, I am so confused!) there is a Thomas LEET in the army in Aldershot. Just a possibility that they were army pals and Frances took william in on the strength of that??