visitor visa from Canada for non Canadian,,,?

[mrmoges]

just a quick question, a friend of mine is a Canadian citizen (as well as his new born child) but the mother still remain a foreign citizen \from Africa/. now, he wants to come to the UK with his wife and child, and as far as i know, a Canadian citizen does not require visa to enter the UK. but can the wife be granted a visa as a dependent if the husband or her sons citizenship to gain visa to UK or does she have to apply independently?

[MPH80]

Hold on - do they want to come here permanently or as visitors?

Your title suggests visitors - the body of your post suggests permanent (talking about citizenship!)