I think it's helpful with researching when the picture is described, so that's what I plan on doing, feel free to add to my list :D
Date: ca. 1850
Beautiful baby in gingham dress. (One thing I love about babies is they never change, a baby is a baby.)
Lady, I'm wildly guessing between the ages 24 and 29. The collar and bow are pretty. I like the whole dress the sleeves, cuffs and Jockey (is that what those short sleeves are?). Rebecca say's her looks are more 1840's, in her opinion.
I love this picture, it's very realistic and beautiful.
Image from: http://www.flickr.com/photos/george_eastman_house/2678298532/in/set-72157606223836462/