Dailinthil is a Bosmer mystic found in the Mages Guild in the city of Firsthold. Entering the Guild before having spoken to Sinien, she'll say, "Here to help? You'll want to speak to Sinien." After you talked to Sinien, she says, "I hope Sinien's plan works. Auri-El watch over you." If spoken to after the siege, she'll say, "It'll be good to see Firsthold return to normal."