Ask HN: Best part-time English editing employment service for spouse?

My wife is a stay-at-home mom but would like to supplement our income. Although her background is in theater (she has an MFA), her English skills and editing abilities are excellent. There are a number of sites which dispense editing work -- oDesk and uni-edit.net are two I've seen discussed here, and a Google search for "editing service" turns up a million more. But we don't know whether any of them are good or bad to work for. Please share any good or bad experiences you've had. If it matters, we are based in the US. Thank you!