Ex.2: 2. Liz's, her 3. John's, their 4. Simon's, their 5. George's 6. Liz's, their 7. Tim's, their 8. his 9. her 10. George's 11. Mary's, John's (his) 12. Simon's, their
Ex.3: 2. She's George's mother. 3. Sarah's Susan and Paul's daughter. 4. They're George's cousins. 5. Tim's Sarah's brother.