If her response exceeded his request, it would indicate that she was truly a baalas chesed. The wife for Yitzchak, the future Matriarch of Klal Yisrael, must be an individual whose character refinement is innate. Rivkah displayed a level of chesed that was exemplary. We may wonder why her willingness to draw water for the camels was so remarkable that it demonstrated her admirable quality of chesed. We suggest that the answer lies in understanding the essence of chesed and its true meaning.
People perform acts of loving-kindness for various reasons.
Some people do it because they actually want to help others. Other individuals do it because they feel good when they make other people feel good. Yet others perform acts of chesed for the recognition they get. True chesed is developing a sensitivity towards another's needs. We feel for other people, and we attempt to provide them with what they need, not with what we need.