I am not sure what you are looking for here. Do you think this is a different Louisa than the St Pancras one and therefore a different possibility for your Thomas?
Alfred and Louisa, with Mary and Charlotte are at 1901 743 /5 /1
They are also in 1911.
*you have answered this whilst I was writing my reply. 
You mention a tree in your earlier post where there is a child added:
Charles Sydney Herbert Harris b 1889 Woolwich. His mothers name was Spiller which is where I got my information re Harris/Spiller.
added
Thanks Monica 
Some time between when that was posted and now, this Louisa Mary Spiller turned up on Ancestry married to Alfred Harris from Woolwich.
https://www.ancestry.com/family-tree/person/tree/9405014/person/122304721326/facts - I believe the same one you were talking about here.
The Charles Sydney Herbert Harris you mentioned is
https://www.ancestry.com/family-tree/person/tree/9405014/person/122312809788/factsThis record for Alfred Harris at
https://www.ancestry.com/family-tree/person/tree/9405014/person/122124775984/facts may not be him (it looks like the poster merged two different Alfred Harrises, but did identify (in the comments) that one of them was from Woolwich.) If it was him, it would suggest he divorced Louisa and remarried, but I think the suggestion of it being two scrambled records is more likely.
Louisa Spiller's dates are mostly plausible except my Grandmother could not have met her as she died 20 years before my gran married Thomas Graham. However this Louisa Spiller doesn't appear to explain the large amount of Welsh ancestry on my mother's side which can only be from my grandfather, as the rest of the tree on that side is well filled out with Scots; *but* Luisa Spiller does appear to have traceable descendants which opens up the possibility of checking for a DNA link if I can find one who has taken a test. So although I don't think it is her, it's a testable hypothesis.
And of course everyone could have been totally misinformed about the possible father and it could have been some 100% Welsh stable boy :-) and it could have indeed been an adoptive mother who my grandmother met as you suggested.
G