Migos is officially bringing Cardi B into the family ... No, Offset's not putting a ring on it, but a collaboration is definitely happening.

We got the group arriving at LAX Wednesday and we asked Quavo -- has Cardi B broken the mold for reality stars who wanna get in the rap game? Cardi, of course, has blown up since "Bodak Yellow" dropped back in June.

Check it out ... Quavo ain't got nothing to say about that, but that's OK because he gives us a much juicier nugget -- Offset's girl is gonna be featured in Migos' third album!!!

Cardi B featured Offset in "Lick" and she's even opened for Migos before.

But this just got real.