Mother of G-d” - I don’t understand why there should be any controversy with that phrase. Anyone who has read the Gospels knows exactly what the word “mother” means there.
If the Catholics would like to focus a bit more on Mary than most, then why not? And if some other group would like to focus a bit more on John the Baptist than most, again why not?
It’s not like either group is putting someone ahead of Christ.
I sure wish Christians would quit picking at each other, and instead think of ways to unite us. What Protestants object to is extra-scriptural Catholic dogmas like Immaculate Conception which says Mary was herself "immaculately conceived" and was completely without original sin. This dogma is actually a fairly recent development in Church history and Catholic Mariology has evolved quite a lot over time.