I don't think it's a good idea to regularly backup your wallet because there's a risk someone will find your backup. One copy is enough, but if you want multiple copies, make sure to create a wallet with an extra word or passphrase as an extra layer of security. Make sure the passphrase is not included in your seed backup so that if it is compromised they cannot find your exact wallet. Two or three backups should be sufficient. As they mentioned, make sure to advise your friend to have a seed backup on the piece of paper.