Antique Style Framed Portrait Miniature After Gainsborough, Georgiana Duchess of Devonshire

Small framed portrait miniature depicting Georgiana, Duchess of Devonshire, after the well-known portrait by Thomas Gainsborough.
The sitter is shown in three-quarter view wearing a wide-brimmed picture hat with pink feather decoration, a red dress with white lace-style fichu, and a yellow rose at the bodice. The portrait is set behind glass in a wooden frame with black inner moulding and a brass hanging ring.
The work is signed in cursive at the lower right. The signature appears to read N. J. Gainsborough.
The piece is sold as a decorative vintage or antique-style portrait miniature after Gainsborough. No claim is made that this is by Thomas Gainsborough or connected to his studio.

Measurements
Frame:
Height: 10 cm / 3.94 in
Width: 9.5 cm / 3.74 in
Depth: 1.5 cm / 0.59 in
Image size:
Height: 7 cm / 2.76 in
Width: 6 cm / 2.36 in

Condition: Good vintage condition with age-related wear.
There is visible dust and surface marking to the glass, minor wear to the wooden frame and black inner moulding.