2. A heterosexual coupla with no children who have lived together for 3 months in a home rented in the sole name of the woman?
3. An unmarried father who lives alone but has contact with his 3 year old son each weekend? The son lives with his mother
4. An elderly woman who has shared her home with a younger man for ten years who acts as her unpaid home help whom she treats as a nephew?
更新1:
5. A married couple with no children who each own their own home and whose jobs mean they live apart for all but 4 weeks a year? 6. A 15 year old girl, orphaned at birth who has grown up in the home of a married couple with 3 children of their own, but was never formally adopted?
更新2:
You are right, definition varies, but whether they are considered to be a family must be reconised by law, if either of the parties die whether they are entitle to share of assest and maintanance.