There's an Ellen Clancy, Widow in 1851 at Strutton Place, which assuming it's near the current Strutton Ground adjoins Great Peter Street
She's 50 from Ireland, a widow and keeps a stall
Also there is sister Ann Sheehan, also a widow from Ireland and keeps a stall, 35
and nephew Jerry Bryan b St Giles, Middx, 7
1479/496/7/26
St John's Westminster should be on FindMyPast
The Bishops Transcripts should be on Ancestry
However, didn't spot anything obvious
Likely to be Catholic?