Heavenly families?

The epistle from St. Paul for yesterday's solemnity contains the following clauses that I've often heard:

For this reason I bow my knees before the Father, from whom every family in heaven and on earth is named... (Eph 3:14-15)

But something struck me for the very first time yesterday. Apparently there are two different domains for families, heaven and earth. Earthly families we're all very familiar with. But what's a heavenly family?

Most likely it's not an earthly family whose members have made it to heaven. Such earthly families are already named on earth, not in heaven. Besides, Jesus communicates to us very clearly that such fleshly relationships don't have much weight in themselves in the world to come through the parable of the seven brothers who married one wife on their successive deaths (Mt 22:23-33, Mk 12:18-27, Lk 20:27-40). When we humans make it to heaven, we will be like angels, Jesus says, which begs the question: can angels have families? So the question remains: what is a heavenly family?

Coincidentally I recently started re-reading The Silmarillion and on the solemnity I turned to the "Valaquenta." The latter speaks of some of the Valar (the gods or highest angels), who are all created by Eru-Illuvatar (the One God) and effectively his children¹, as being siblings². What makes them siblings? Certainly it isn't parentage, since they are all equally created from the thought of Eru. Is there some other sort of grouping that's analogous to family relationships?

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Notes

1. Though of course not "Children of Illuvatar" (i.e., elves and men).

2. Námo and Irmo are said to be brothers, whose sister is Nienna. And Vána is younger sister to Yavanna.