Carol, I think they could call themselves whatever they wished (married, single, widow etc) - no proof of age or identity or other documentation would have been required. We also don't know Harriett's state of mind or if, or how, any of her actions related to her clasification in the 1911 census, or even it's accuracy.
I hope for more luck for you.

Has anyone (presumably local) come forward to volunteer to do lookups of police records or workhouse records?
PS. I am not sure how strict the GRO are with spellings (someone else may know), if you are going to order b/cs for Alice and John and want to specify mother as Harriett, might it be wise to spell her name Har(r)iet(t). Surely they would issue no matter how the name is spelled though?

I am probably just being paranoid but I think you used to have to spell the name exactly as it appeared in the index eg, if the name was indexed as Byrd but you knew it should be Bird and ordered it with the spelling as Bird, I thought that they would not issue it .
