I mistakenly set my gmail account on my mum's phone the a few months ago because I wanted to avoid the whole process of having to sign up on Google. But now I have created an email for her and actually added it on her phone. UNfortunately I dont see how to remove my account from the phone using android 4.4.2.
You should go to the phone settings, and go under accounts and then select the gmail account that you want to remove and click on the menu button in the top corner to remove the account. This process might be a little different based on the OEM of the phone, since they might theme the operating system.