Daya's affinity is water, of course. In hindsight this is so obvious that she's not sure why her parents even bothered with a divination. She has always wanted to be at sea, and when she was a small child she spent many months with her cousins in the south, begging to be on the coast where the ocean was. The common wisdom is that water affinities are useless inside the school, although she's not entirely sure she buys it. Human beings are mostly made of water, they rely on it to live, and their natural sources of it within the school are supposedly some of the more dangerous places inside it.
Even if everyone is right, though, Daya isn't worried. You don't need a good affinity to survive in the Scholomance, you just need to be good, and she is good. She's good at things, and she's a good person. These are related, because people tend to be reduced to evil when desperate. Daya has decided never to be desperate. She will comport herself with honor and uphold the name of her family and her enclave. She will not consider resorting to anything so low as relying on malia at any point. Nobody from the Jaipur enclave ever does, but Daya intends to take it a step further; she will be a stabilizing influence on her entire year, on the entire school, and if anyone is obviously maleficing, or actually killing other students in order to feed on their mana - she knows that happens inside, horrible as it is, as much as it makes you the very same thing as the monsters that the school was built to keep out - she will put a stop to it, harshly and immediately, and then perhaps it will not happen again.
Daya knows ten languages, because her intention is to focus on languages to the relative exclusion of artificing or alchemy or writing her own spells. She doesn't expect this to be particularly limiting. Ancient wizarding traditions contain an incredible wealth of stored knowledge, and it's unlikely that she'd be able to do better than that on her own, while still a child. So she has Hindi, English, Latin, Mandarin, Classical Chinese, Sanskrit, Tamil, Telugu, Kannada, and Malayalam. She packs the standard array of useful items for wizards who are focused on neither alchemy nor artificing, with very little personalization, because she is sure that her parents and grandparents have been thinking about this topic for longer than she has been alive. She also brings her father's enchanted sword, which is heavy but certainly worth it, in terms of ability to defend herself.
Occasionally, in the private corners of her own mind, even though she knows she shouldn't be, Daya is grateful for mals, even though she hates them with ever fiber of her being, for wanting to kill her and for killing so many others of her kind. If they did not exist, there would be no need for wizards to carry enchanted swords or to spend long hours learning how to use them, and enchanted swords are lovely.
Neither she nor her parents worry, in the hours leading up to induction. Worrying is pointless. She will ensure that they see her again in four years.