In many places in Mark, the examples of faith come from women. And Mark 14 is no different.
Here, Jesus' death is plotted, then a beautiful act from a nameless woman, and then Jesus' death is planned. In the middle, Mark is trying to convey something very important. Essentially, if Jesus is not firs tin your delight and devotion, he might as well be last. It is a warning, but an important one nonetheless.
Those of us in church are especially vulnerable to having Jesus slipping down in importance without even knowing it. We must take head and continually give ourselves completely to the Lord.