This story is a bit of a change of pace for Hera—in some ways at least. Usually, the queen of gods keeps herself busy by tormenting one of her husband Zeus's lovers. She also spends a ton of time making the life of Heracles as frustrating as possible. In the tale of Jason and the Golden Fleece, however, she actually helps the young hero out. Now this is a Hera we could get used to!
Hera injects herself in a critical plot-point as she instructs her daughter Aphrodite to send Eros to make Medea fall in love with Jason. Without the help of love-smitten Medea, Jason would never have been able to nab the Golden Fleece. Of course, if you dig a little deeper, you learn that the reason she favors Jason is because she really really hates his rival, Pelias. So, maybe Hera's favoritism of Jason is just another form of her usual nastiness. We also hear that Jason once carried an old woman across a stream in a storm, losing a sandal in the process. When he reached the other side, the old crone turned out to be none other than Hera. Way to luck out, Jason!