Pastor William Mulroney - Sam and the Pastor seem to have a complicated relationship. Apparently before the outbreak, Sam volunteered with the Pastor at soup kitchens, helping him serve food to those who came by. It is showed during the cutscene during which the Pastor informs Sam she wasn't at the service previously, that Sam tends to get easily fed up with the Pastor's constantly-passive attitude. Although, after the Pastor catches Black Fever, falls ill, and is (eventually) shot by Alan, that Sam, sounding on the verge of tears, is furious with Alan that he didn't ask the others what they thought should be done, showing that Sam cares deeply for the Pastor.
Lily Ritter - Not much is known about the relationship between Lily and Sam, except that Sam risked her life during the Mission: The Vet Clinic to secure meds that Lily needs to survive.