Scree meets Aino first in The Temple. She's in the process of being sacrificed to the Leviathans - the Undine gods of the sea. King Adaro, her husband and current King of Aquis, has decided sacrificing her to the gods would help reverse the taint of the water.
Scree convinces Aino that there are other methods and Aino gives unto Scree Jen's Undine aspect. Jen then being able to swim the the waters of Aquis, embarks on a mission from Aino to cleanse the waters of Aquis from a toxin which was what had caused her husband to make such a rash decision of sacrifice.
Having killed her husband and cleansed the waters, Aino once more presents herself to Jen and Scree claiming that she is grateful for their service and that more Undine than she realised had survived in hidden lagoons elsewhere in the realm. It is assumed that Queen Aino is then the leading authority figure in the realm, due to her husband's loss.
Spoilers end here.
Trivia
The name "Aino", meaning "the only one" in Finnish, was invented by Elias Lönnrot who composed the Kalevala. In the epic poem, she is a beautiful girl who drowns herself rather than marry the elderly Väinämöinen. In the game, Queen Aino permits her husband to drown her in air as a sacrifice to reverse the taint in the water.