It may just take a while for it to take effect. If it still doesn't change then you should email the help team who should be able to change it for you.
To unprotect your tweets go to settings and uncheck the protect tweets box.
You can't, you can only unprotect them on the web version.
You can't do this. You either protect your tweets and approve people to follow you or you unprotect your account and your tweets are viewable and anyone can follow you.
If your tweets are protected then only people following you can see your tweets. If she isn't following you then maybe she has access to an account that is following you.
No Mel Gibson is not on facebook but he is on Twitter but he has protected his tweets.
Yes he does. His username is 'DylanSprouse1' but he has protected his tweets so you need to send a request to see his tweets.
Any Twitter user can send you a tweet if your account/tweets aren't protected.
Yes, you don't need an account to access Twitter. If the person's account is public, and you know his/her Twitter handle (username), the URL of the account's tweets will be https://twitter.com/________ and fill in the blank with the person's Twitter handle.
Yes they will become public.
If you have protected tweets, you will see a follower request on the right hand side sidebar of your homepage. Click on it and you can decide if you want to accept or deny the request. If you don't have protected tweets, anyone can follow you without your permission.
People won't be able to use the Retweet function on your tweets if your tweets are protected. This doesn't stop them copying and pasting your tweet and retweeting the old way though.
Yes anybody can read your tweets. Twitter is a big great tool.