vayeitzei - Why does the torah tell us Rachel was a shepherdess (Genesis 29:9)?

Within Genesis 29 the story around the well is described and while Ya'akov talks with the local shepherds it says something like this: While Ya'akov spoke with them, Rachel came, with the flock of her father; for she was a shepherdess.

Why was it so important to state that Rachel was a shepherdess? The verse already teaches that she came with the flock of her father, and the daughters of Yitro aren't called shepherdesses (see Exodus 2:16 & 19). Is there a more important reason why she is entitled this way?