Or rather, why is the mother of Jesus exclusively written μαριαμ, and the others inconsistently either μαρια or μαριαμ?
I was originally prompted by a mini quest into the original meaning of the Hebrew name underlying μαριαμ in the New Testament, and so went a searching.
Now I'm using the Greek from the ISA Scriptura Analyzer because it allows me to profile usages very well, but texts will of course vary. But consulting the Nestle-Aland 28 for Matthew 27:61, however, there seems to be a real convention here, I think, not just sloppy scribal work.
Jesus' mother: μαριαμ
Matthew 1:20; 13:55; Luke 1:27; 1:30, 34, 38, 39, 46, 56; 2:5, 16, 19, 34; Acts 1:14
Other Marys: μαριαμ
Matthew 27:61; John 11:28; 20:1, 16, 18
Jesus' mother: μαρια
Other Marys: μαρια
Matthew 27:56; 28:1; Mark 15:40, 47; 16:1, 9; Luke 8:2; 10:42; 24:10; John 11:2, 20, 32; 12:3; 19:25; 20:11
(I've omitted instances of μαριας because sadly they don't help either way: but they are Mt 1:16, 18; 2:11, Mk 6:3; Lk 1:41; 10:39; Jn 11:1; Acts 12:12, of which the last three refer to other Marys)
Based on what seems to be a strong case that the authors of the New Testament made sure Mary was only ever written μαριαμ (for whatever reason, whether her name was actually different from the other Marys, or whatever else; this being extremely unlikely), and the overwhelming amount of times, only calling other Marys μαρια, I conjecture that writing the name of the other Mary's as μαριαμ is a scribal slip in these instances.
How is this inconsistency/strange consistency when it comes to Mary the mother of Jesus' name to be explained?
Thanks in advance.