Gamora has no idea who the twins were, or really any of the names that she said, other than Star Lord. That would be Quill, and there is a slight look of fond exasperation on her face. Well, he appears to have gotten that name to stick, at least here...

Rolling her head slightly side to side, she comments, "I do not believe I am familiar with this Stark or Buckys."

Names, she assumes, although one never can tell. "Back where you are from? Or has Quill been announcing his presence her that greatly that all now know?"