Sure! We do not limit who you can host websites for. However note that if you plan on giving this person access to your web hosting control panel account they will have full access to your hosting account and can make changes, delete websites, databases, email accounts, files etc. at will.
So while you can do this, we recommend you do not give them your control panel credentials for security reasons, or that they purchase their own separate hosting account. It is your responsibility to keep your account details secure, we not are not responsible for any damages that may result from someone else purposely or accidentally deleting any items.