Oh. So sorry for your loss of your rooster.
Your hen just had a shock and is dealing with it as most hens do by not laying for a while. It's been my experience when hens have gone through a shock that it takes them about two weeks to go back to laying if everything stays calm for those two weeks and no more shocks occur.
However, you may need to get her laying more quickly than that if you want to keep the possibility of fertilized eggs alive. I know hens save semen in a reservoir while laying, possibly for up to three weeks, but I don't know what happens to that reserve of semen if she stops laying. So, to get her laying again quickly, if it's possible, I would give her 1/2 to 1 ounces of fish each day. I would not give her extra grain or other treats. The protein might get her back on track. For all we know, she may have done what many animals do when missing a dear companion and that is lessened how much she is eating which, of course, will affect egg production. Maybe also moisten her complete balanced layer feed with some broth or milk to tempt her to eat.
If you've still got any eggs available, even in the fridge, I'd be giving them a try in the incubator. I think things are that desperate if you really want some of his little chicks running around, but even that is getting to be a little of a long shot, too, at this point.
My old hens, and a few that are even 5 years old and still laying, don't mind younger male attention at all once they've gotten used to his presence. I'm not sure older hens want a break from male attention in the same way that some older women do. If a four-year-old hen is ovulating (laying an egg), then she living with the same hormones that she lived with at age 2 and will be responding to those hormones in the same instinctual way. Of course, there's a balance involved between how many hens to how many roosters, too. So ....