Hello, Kudo's to you and your friend for taking on such a huge task. We had to care for kittens a long time ago who's mother was also hit by a car. We were lucky at the time our Dog had milk from nursing her puppies that were already gone (I think they can produce it somehow afterward if it's needed). Anyway she amazingly took over the kittens but wasn't able to provide enough milk so we got baby milk (from somewhere, it was so long ago I don't remember) and got tiny bottles for them.
One very handy thing your friend can do is fill them up, make sure the milk is luke-warm, not hot or cold and then just make a little holster for them (or if they are completely full, lay them in the bed with them) so that you can leave the bottles there for a couple hours. The milk will still be fine after a few hours as long as it was fresh when you took it out of the fridge. This way if she has to leave at all, they still can get to their milk and someone can just refill them or take them out if they are at the point where they shouldn't be consumed anymore. I would say about 2-3 hours the milk will be ok, it's still ok after that for a bit but take it away before it even gets close to that point!
Hope that helps
