The girl who gave water to Eliezer and his caravan was indeed Rebecca, Abraham’s grandniece. After having betrothed Rebecca to Isaac, Eliezer met Rebecca’s family and told them the details of his mission.
G‑d Spares Nothing
וַתֵּלֶד שָׂרָה אֵשֶׁת אֲדֹנִי בֵן לַאדֹנִי אַחֲרֵי זִקְנָתָהּ וַיִּתֶּן לוֹ אֶת כָּל אֲשֶׁר לוֹ: (בראשית כד:לו)
[Eliezer said to Rebecca’s family,] “My master’s wife Sarah bore my master a son after she had grown old, and he gave [his son, Isaac,] all that he owned.” Genesis 24:36

Abraham was willing to give up his entire fortune in order to ensure that Isaac marry Rebecca. So, too, G‑d is willing to give up “all His bounty” to help each and every one of us fulfill our mission of bringing about the “marriage” of the physical and the spiritual dimensions of reality by transforming the world into G‑d’s home through our good deeds.1