It's lovely but it would be difficult to use. My daughter's name is
Miriam and she is often called
Marian /
Mary / etc. And the spellings I've seen - Merium is the onee that still takes the cake.
For me, I wouldn't use it. It would be so confusing to so many people. My name was unusual when I was growing up (trendy now) and it was a pain - even though
Haven is pretty easy to spell and pronounce!
Miriam, too, is fairly easy but as I said it's often mistaken for more common names and often spelled
Mariam.