Ah, the much vaunted photos appear

Top one late 1860s. The lady is wearing an 1860s style skirt but without the hoop petticoat which disappeared in about 1868, and a shawl which obscures her bodice and was a sort of universal old-lady custom of dress. Could be a little later as older women didn't always dress the latest, but the back shows the simple style of the 1860s.
See how the floor is a little out of focus? Early camera lenses had limitations.
Bottom photo, hard to date the clothing style but the photo style is a hard-edged oval, not seen before about 1870 and very popular in the late 1870s. The back also shows a late 1870s/early 1880s design.
Cheers,
China