My Fireplace Ships to Dragon Realm

The dragons on the other side of Emily's fireplace call her the Dragon God. She is only an heiress hiding from relatives who want her dead for a fortune, and the mistake follows her every time she opens the flue and starts costing her more than she planned to give. She runs to her family's old farm because it is the one place left that nobody watches. The fireplace in the main room has not been used in years. When she finally lights it, the flames pull back instead of catching, and on the other side is a hall of stone with a dragon lying in it, poisoned, close to dying. His name is Kael, lord of the metal dragons, and his people are losing a war she knows nothing about. She starts small. Firewood, aspirin, blankets. Then rifles, because firewood does not stop an army. Every parcel she pushes through the hearth changes something on the other side, a skirmish won, a village resupplied, a wound closed that should have killed him. The dragons start leaving offerings at the fireplace before she even opens it. They have decided she is not a woman helping a stranger but a god who chose their side.