If you have a close bond with someone, you ask them to be your family member. This can be twins, sisters, brothers, siblings, cousins, triplets, or even husband and wife/wife and wife/husband and husband.
How to Get A NaNo Family Member
You can ask them! It's okay if you're nervous, and they might say no, but that's okay. Information about getting a NaNo husband/wife is still unknown, however.....Volunteers of information would be appreciated!