The Thirst Quencher is a store owned by Miracle's mother, Wizard. With her being pregnant with a foal, Miracle has interimly taken over the business. It also serves as Miracle's residence.
The owner is back in town and she's extremely busy. She'll be making preparations for her store in time for the grand opening next Friday. (the 9th of March)
Twilight, I can't help it! Someone needs to help Twitterponies Wiki by adding more information.