She is probably the Henrietta Shuckburgh who married William Collins. They married in 1828 in Downton, Wiltshire, UK. If this is that Henrietta Shuckburgh, she died in New Zealand.
From Wikimedia; removed large spots in the background and fixed parts of the left, bottom, and right edges with Photoshop.
Henrietta’s coiffure looks Victorian with straight hair parted in the middle. The dress is British Regency.
Keywords: 1820, Carpenter - Margaret, Henrietta Shuckburgh, Shuckburgh family, Collins family, straight coiffure, large curl bun, fichu, Empire bodice, décolletage, quarter length full sleeves, tight cuffs, Empire waistline, A-line skirt