Are you sure about the last syllable? Is it a long or a short 'I''? Look at these lines from Shakespeare's "As You Like It"I
Her worth, being mounted on the wind,
Through all the world bears Rosalind.
All the pictures fairest lined
Are but black to Rosalind.
And how do you know that the 'S' sounds like a 'Z'? Maybe it's ROE-sa-lind, or ROSS-a-lind.
I tend to think the name is a combination of the names "Rose" and "Linda", and say "ROZE-a-lind".
But that's just me. Well, also Wikipedia says that's the way to pronounce the moon of Uranus that was named after the Shakespeare character.