You can invite any members of your immediate family to join. If theyâ€re not already members, theyâ€ll just need to register first before you can add them. Immediate family members include the following: Husband, Wife, Partner, Son, Stepâ€‘Son, Daughter, Stepâ€‘Daughter, Mother, Motherâ€‘inâ€‘Law, Stepâ€‘Mother, Father, Fatherâ€‘inâ€‘Law, Stepâ€‘Father, Brother, Sister, Granddaughter, Grandson .