Update: Checked the hive yesterday and there were queen cells. Put apivar straps in and closed them up. Sadly the queen died in the attack but they're taking action on the saved brood. My next question is, is it too late for her to mate? I live in Northern California and we're still getting temps up to 90? so I would assume there's still time for her to get mated. And if she can't will they be able to make it through the winter with a virgin queen?
It depends ... ;) Yes, if the bee population age is young enough they will make it through winter just fine. She would emerge in the spring as a drone layer or a laying worker hive. Now ... looking at your location of California, you do not really get any winter to speak of (by my standard); the hive dynamics will be different in your conditions.
So what you should do is give her 24-28 days from now to see a laying queen. If you do not see nice egg pattern by then, buy a mated queen to get the hive restarted or combine it with another hive at that time. The recovery window by then will be small because the bees will be old, so either buy the queen now or have your source picked and ready for if needed. ..
Looking at where we are at on the bee calendar and the fact that queens will be low and slow laying for the next couple months, even a new queen. ... Really, you should just call it a loss now and combine them with another hive. You can split them out in the Spring when they are ramping up, to get your hive numbers back then.
Hope that helps!