Jumping in here as Jim is in a different time zone so, knowing Jim's every thought, I can safely say that he'd tell you it's later than 1912
For one thing, the v-necked collar style didn't even start until about 1913-1914, so even if this lady is on the cutting edge of fashion she wouldn't be wearing that neckline in 1912.
For another thing, the untucked blouse is a style that as far as I know was unheard of, for a lady, at that time. I've been trying to find out when it was first seen, without any luck, but I'd think it's relatively recent.
The first photo, I agree with Jim...pleats were an 1870s thing but this outfit has the sleek look of 1880s, so very late 70s' maybe, but more likely early 1880s.
Cheers,
China
