That's not a story she's in any hurry to tell. She can understand why Kylo might've wanted to leave some of it for later, especially considering Leia's presence here. Telling his grandfather that he's turned against his family doesn't seem like the kind of thing that would land entirely well -- but there's no keeping it a secret, either.

"I stole his father's ship."

Best to start at the beginning.

"The person I worked for had it for a few years, just sitting there unused. A runaway Stormtrooper and a droid needed off the planet and I was the nearest pilot. Then Han Solo found us and brought me to Leia's Resistance after it became clear I could use the Force."

She isn't in much of a hurry to explain how that happened, not least because it ends in having to explain how she and Kylo broke Vader's -- no, Anakin's -- old saber.