Ok so this might be a long shot but I shall keep trying

I found a Maggy Marshall in Eastbourne... aged 18 in the 1901 census.
Sussex > Eastbourne > District 12
Piece 881 Folio 19 Page number 29
Schedule 181 at 18 Pevensey Road
Head is a William Everest and Emma Everest. Maggy is a cousin and in-laws also listed with surnames Pierce and Ayers.... with births in London.
So... if we can find an Everest / Pierce / Ayes related to James/Alice (that is James Marshall senior or Mary Ann's maiden name) then I think we have the jig-saw complete. Am I thinking that right?
It would make sense if there was a cousin the same age in Eastbourne to help out.... the parents may have abandoned them but surely the aunts and uncles would have a part to play.
Equally keen to rule that out if not the case.