Shaun, a brilliant find. That has to be them in the 1891 census.
So Thomas Clarkes birth registration is
CLARK, THOMAS Mother: HUME
GRO Reference: 1891 M Quarter in HELMSLEY Volume 09D Page 448
Hume was another of the names that Elizabeth used I know where that comes from.
HUME was a family name. Elizabeth's father was Andrew
Hume LYONS
Thomas baptism that I have been looking for was in Kirkdale on 12th March 1891.
Thomas, son of Elizabeth and Thomas Clarke. Abode Nawton. Father "a soldier"
https://imgur.com/a/rIW1rSu