C.1891 carte de visite of a young lady. Note how she is wearing a bowler hat instead of a top hat. Only married women wore the top hats, so the bowler fits in nicely with the subjects age.
In the next century, bowlers for sidesaddle riding would become acceptable for informal hacking. The bodice is still very tight fitting as in the 1880's, but is starting to look slightly more like a riding jacket than a bodice.
Note the "kick up" sleeves that were fashionable on bodices during the early 1890's. We also notice that her skirt is less full than it was in other decades and would continue to get more slimmer and tailored into the 20th century to become the traditional riding apron we have today.