There are many YEMM family units from around the Lydbrook/ Ruardean/ Reddings area of the Forest.

If the one you are looking for is shown as a Coal miner from Lydbrook in Featherstone Yorks in 1881 census, with wife Ellen, then I suspect this is them with young family before they moved north.

In 1851 West Dean

YEM George 33 Collier West Dean
Ellen 33 Lydney
George 11 Tredgar Wales
Paulina 6 East Dean
Benjamin 4 East Dean
David 1 West Dean

In 1871
David is a Miner in Worksop Nottinghamshire