I just find someone with the description "... is very weak" and assign the position to them. If i can I will try and make a willow hammer (or adamantine once I get it) or some other feather light material to make sure they do little damage.
Of course, I also have some chains next to beds in little 2x2 cells, but still.
Oh, and in my current fort the Sheriff had her newborn (third) son stolen not a month after he was born. Not sure how it happened, unfortunately. No combat notice about a goblin or anything, so I guess she put him down to pick up the lumber I hadn't told her not to haul yet and didn't see the gobo come up behind them. There were some greenies skulking about, so I know it was them, I just didn't get a notice at that time. I also added the children to the burrow so they aren't supposed to leave now -- guess I should have done that sooner.
Its gonna be interesting if that dwarf comes back with a goblin siege later, as I plan on making the Sheriff's first (or second if the eldest isn't around) son the new Sheriff/CotG once the time comes. Brother against brother!
[edit] and right after I post this, I go back to Sakrithalath (Blazedbolts), and almost immediately get a message that the Sheriff has given birth to a fourth son. Prolific couple, that Sheriff and her husband ... I wonder if she'll be able to keep this one with her until it can mature.