I pronounce
Noel as NO-ul and
Noelle as no-EL. I've seen
Noel as a female name before, so I'd assume it was pronounced like the male version.
Daniel on a female would confuse me a lot, and I'd immediately think it was a typo! - but if I knew it wasn't, I'd probably assume they'd spelt it that way because they wanted the dan-yul pronunciation, and not dan-YELL.