Leia's message explains that R2 contains the plans to the Death Star, which must be sent to her father on her home planet of Alderaan; she then says that Obi-Wan owes her family for covering up his "little problem".
R2 contains the plans to the Death Star. This is what Leia's message explains. The Death Star must be sent to her father on her home planet of Alderaan. Obi-Wan owes her family for covering up his "little problem". This is what she says.