When Shir steals something from a store on Dezo, she goes straight to Rolf's house. How does she get there? There's only one spaceship, and it's still at Skure even with Shir in Paseo.
Ah, but there is at least one other spaceship that we know of: the Landale. That is where my theory about Shir and Tyler comes into play. Tyler is a space pirate and Shir is a thief (and a compulsive one at that). Match made in Heaven!