My wife was denied by a male nurse for a female nurse to help her clean up. Is this legal?

Why don't you explain the circumstances regarding this. Were there no female nurses available? Clean up what? Herself?

More details would help. Did she ask to speak the nurse supervisor?

I doubt if it is illegal. But it might violate some institutional policy.

It doesn't break any laws here, nor is it against any institutional policies. We have quite a few male nurses working. Usually means no female nurses available on demand.