Messager.
Every time you write or draw on your arm when you get bored, the ink shows up in the exact same spot on your soulmate's arm as well. For years, they've been sending her cute doodles and love notes this way, and now she's finally replying. When they happen to appear at her place of business, they see the ink that they wrote her that day. While she checks the time, she spots a new message written on her wrist.
Every time you write or draw on your arm when you get bored, the ink shows up in the exact same spot on your soulmate's arm as well. For years, they've been sending her cute doodles and love notes this way, and now she's finally replying. When they happen to appear at her place of business, they see the ink that they wrote her that day. While she checks the time, she spots a new message written on her wrist.