And no, I wouldn't throw the older hen into a large flock on her own. That would be very unfair on her. She's probably bewildered and grieving the loss of her pal, and if she were to go into a large flock all alone while she's feeling a bit low she might end up at the bottom of the pecking order herself. It could be very tough on her.
Try and persevere with getting her chummed-up with a new companion.
Try and persevere with getting her chummed-up with a new companion.