I just came across an entry for a Charlotte Eliza Walker who, with her husband Thomas Collier Walker, were Stewards of St Luke's Hospital in Middlesex (1851 and 1881 censuses and see http://www.mdx.ac.uk/www/study/4_13_ta.htm). Charlotte was born in 1815 in Douglas.
I was intrigued so traced this back and found that she was Charlotte Eliza Lyell chr 15 Jun 1815, St Matthews, Douglas to ?Lyell and Margaret Dick. She had a brother John Thomas Stewart Lyell born 1812 in Douglas.
Charlotte married Thomas Collier Walker of Fife on 20 Jan 1833 at Duddingstone, Midlothian. Two children are listed with them, George Lyell Walker and Margaret Jane Walker both born in Scotland.
This family would seem to be linked to Richard Lyell Walker who married Margaret Brew?