Don't panic. She's own root and even if you have to prune most of that cane off (and you do have to prune off any dead wood) she should put up some new ones this spring. It's still way too cold for that to happen though.

I don't know where you are but if you aren't past your last frost date you could put some leaves around it. It's a little late but it couldn't hurt.

As I said, you do have to prune off any dead wood. Starting at the top clip off a small piece and look at the center. If it's whitish/cream green it's alive. If it's dark brown or tan it isn't. Keep clipping down in small pieces until you find that whiter center. From there down it should be live cane. (I'm going to be doing a LOT of that myself this year.) It's way too early to do any pruning here but where you are it may be time. Usually a good rule of thumb is to start your pruning when the forsythias begin to bloom in your area.

Being own root I'd say no, she isn't dead. But she will take time to sprout new canes from the roots so be patient. It may not happen until it gets MUCH warmer. I've had roses I was sure were dead sprout new growth as late a mid-June. They just needed more warmth for longer to wake up.

You can give her some organic fertilizer but do so sparingly. You don't want to kill her with kindness. I wouldn't suggest any chemical fertilizers until you see strong new growth on her. You don't want to burn the roots.

As for the neighborhood kids, maybe you should put a cage around her some how so they can't get to her. I have a bed on the edge of the street too and fencing it did help keep the kids (and dogs) out of it.

I think I see some green at the bottom. Throw some clean bark mulch down and protect her until it is your time to prune. I bet you will find new growth when you uncover. I had the same situation in Chicago....never got around to protecting them. I think she will be ok. Remember the bunnies like the tender new shoots.

And then there are some people who don't ever consider covering their roses for winter...and the roses survive, even in zone 4 (Me.) Your baby looks good and green at the base to me - so don't despair. Follow the pruning instructions already mentioned but not for a while yet - not until the weather settles into spring a bit further and watch for the yellow forsythia bloom as Seil says for your cue.
I have pruned own root (and grafted, too) roses right down to soil level and have had plenty of bloom that season. All will be well.