When you are talking about records before 1700 in English, I don't think "misspelling" is the proper term. Spelling simply was not "set" back then. People would spell their own name in different ways in the same document, and no one thought anything of it. The spelling of regular words didn't begin to become regularized until the KingJames Bible, which was about the time your ancestor was being born. So Daniell before 1700 would simply be an alternative spelling of Daniel.