What does Aunt Ada Doom want on the morning of Elfine's wedding and what might her request symbolize?

Flora spokes to Aunt Ada, who only wants a "Hell's Angel" (a concoction with brandy, an egg, some cream and ice) for breakfast. This may symbolize the probability that Aunt Ada Doom is going to become something like a "Hell's Angel." It might be for good reason that Reuben is nervous about Aunt Ada Doom's request.