"familiares" means "servants, housemates" at least in all Latin German-Dictionary I have consulted. It also can mean familiar (Vertrauter /te) . The latin word for a relative is propinquus or cognatus, (and more ....) In an English Dictionary I found "familiar acquaintance/friend" or "member of household (family/servant/esp. slave)."
In my dictionary, it means servants, housemates OR friends of the family.
Translated by "relatives" in English, doesn't sound 100% right, as relatives mean mainly "someone who has the same blood, parents"
For instance Oxford's definition:
A person connected by blood or marriage.
‘much of my time is spent visiting relatives’
I guess the reason is because there are no exact translation in English for this term. Familiares means the extended family, with slaves, servants, daughters, sons, all the people in the household depending from the paterfamilias. (In some context, it seems it could also mean extended family as cousins and very close family's friends).
As the definition of the family changed, it's not a wonder we meet difficulties to find an exact translation.
"Relatives" is maybe not a good translation, but it's probably the less bad, the closest.