I would get a friend or neighbor who could look in on the broody and hatching chicks.
It would be even more important to have someone there to put "plan B" into effect should something start to go wrong. You're dealing with unknowns - whether the broody will handle her brood okay, defending them against other chickens who might want to do them harm, whether the chicks will get enough water and food in their first important few days.
As for the nipples, I would provide a conventional water source for the first few days at least so you know the chicks are drinking. It does take awhile for the broody to teach her chicks to use the nipples, especially the horizontal ones, being harder for tiny beaks to activate than vertical ones.