The obvious fit is Melinda Davis, daughter of George and Jane. Born c1843 In Longney, living there with her parents on 1851
Piece 1963, folio 7, p7
1861 - visiting the Merritt family in Gloucester
b c1842, Longley
Piece 1765, folio 8, p9
However, I don;'t think this is yours, as she's from the other side of the river from the Forest, and censuses after she's married suggest she's from Ruardean area, Also there's a marriage in 1882 in Gloucester of a Melinda Davis, b c1842, father George. She's with her future husband, using his name, in 1881, and is b Longney
At least she's counted out!