Ответ:

  1. This is my mum. Her name is Anna.
  2. Tom is cool. His hobby is football.
  3. They’re friends and their names are Rocco and Carla.
  4. We are brothers and our hobby is sport.
  5. Dave’s best friend is John.
  6. My dad’s name is Bill.

Местоимения выбираются по лицу и числу владельца: her — её, his — его, their — их, our — наш/наша; для принадлежности используются апострофы в Dave’s и dad’s.