It's cute and definitely ok.
I think it looks visually quite cute, kind of like Dixie or Dottie. That said, be prepared for a while life of people spelling it wrong, not just for you to deal with but for Rubie herself. I had a name that was unusual for the time, and I was a shy kid, and though people could hear it, they couldn't figure out how to spell it, and it made me wince and want to hide especially in elementary school if I would have to correct an adult, or explain my name in front of a whole classroom of strangers. I like my name, but didn't like that.
It seems fine to me, I like it!
It's cute and it's not an outrageous spelling where it will be hard to even pronounce correctly. I say go with it.