A couple of points to set the stage for my question. Please bear with me:
1. The prophecies about Christ being born of the tribe of Judah refers to both St. Joseph and St. Mary (I have no reference for this. This is what I was taught as church tradition).
2. Numbers 36:6-7 says the Israelites are not to marry outside their tribe for inheritance reasons.
3. The priests of the Israelites came from the tribe of Levi. Therefore St. Zacharias, the father of St. John the Baptist, was a Levite.
4. By virtue of point 2, St. Elizabeth, the wife of St. Zacharias, must also have been a Levite.
The bottom line of all this is that St. Mary is of the tribe of Judah and St. Elizabeth is of the tribe of Levi. But if that is true, how can they be relatives (Luke 1:36) according to point 2?
I'd love to get OO and EO perspectives on this.