Not-so-hidden mother & baby—ca. 1865 full plate tintype
Full plate "hidden mother" tintype, probably from around 1865 judging from the gingham print and the fullness of the mother's dress and sleeves. Not sure if the little towhead is a boy or a girl, as the fluff of hair and the dress don't give us much to go on for gender in that era.
Theories abound on images like this, and there is speculation that photographers' assistants, not mothers, hide under the drapery and hold the small, squirming children. Be that as it may (and maybe because I've got a little one just this age), I'd still like to think it's the mum underneath—a little tired, a little disheveled and happy to duck the photographer's exacting gaze, but always, always there as an "invisible" but ever-present part of her child.