When she isn't busy sprinting across the tundra to give you a letter from a "Friend," you can actually recruit her to join your party.
She completely replaces the vanilla male courier with a custom-voiced female NPC.
When she’s off the clock, you can usually find her hanging out in Belethor’s General Goods in Whiterun. A Few Tips for Your Load Order:
Tired of the same old "I've been looking for you. Got something I'm supposed to deliver—your hands only" from that scrawny vanilla courier? It’s time for a change.