How can I find a good place to to send a parenting essay?
Well, this might seem obvious, but the place way to find outlets is to read those outlets. I've said it before here, but editors can get quite peeved when people submit to them and the mag doesn't actually cover said material. So I'd be sure to flip through the mags you plan to submit to before doing so.
That said, Cookie runs a lot of essays, Parenting usually runs (I think) about one per issue, as does American Baby, and Parents runs the occasional one. But there are sooooo many other options out there: your local paper, bigger papers like the Christian Science Monitor, and a ton of websites. Just google "parenting essays" (without the quotes), and you come up with a lot of options.
Good luck! And what say you readers? Do you have favorite outlets for your essays about your adorable tots?