How did Mary find favor with God?

[Dave...]

If we have nothing to boast about, how did she find favor with God?

Does this passage tell us anything?

Romans 9"11-13 (for the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls), it was said to her, "The older shall serve the younger." As it is written, "Jacob I have loved, but Esau I have hated."

 

[Whatever]

The word "favor" there is in the Greek charis.
The King James translates this word "Grace" 130 times and only "favor" 6 times.

It means that Mary found grace from God.
From Vincent's Word Studies:
The higher Christian signification, based on the emphasis of freeness in the gift or favor, and, as commonly in New Testament, denoting the free, spontaneous, absolute loving-kindness of God toward men, and so contrasted with debt, law, works, sin.