I suspect this might be another transition dress – a dress from the 1860s that has been remade to suit the changing skirt styles of the 1870s. The volumes of fabric used on 1860s and earlier skirts made these prime candidates for remaking as skirt fashions changed. There was plenty of extra fabric to work with. In the early 1870s, I suspect women would have simply reused the existing bodice. This bodice has the wide round look that was popular in the ’60s. There is now an apron and a drape you can just see in the back. Remaking a dress was an economical use of existing clothing to create a new wardrobe.
This lady sat for her portrait at H. G. Pearce, Photographer, Providence.