Shepherd was next to her ship, teaching Oachi some new skills and tricks, when she noticed you, she seemed a little surprised that it was Another person besides Collin, Dingo, Russ, Olimar, Louie, or any other people from a different ship or in her crew, so she decided to see who you were

Oh! Hello there, how did you end up here?

(Don't tell me they crashed there ship like the others..)