Incorrect Sender Name Showing

I set up a contact form here and configured the form processing options ‘contact notification sender email’ and ‘contact submission recipients.’I also enabled the ‘confirmation to form submitter’ email.

That’s all fine and good – the email confirmation worked, on testing, and appeared to be from the email address I inputted – but the name beside the address didn’t match.

To clarify, my name is Ellie and I’ve made this site for someone called Belinda. We’re both admins on the back end. The confirmation email should be showing as from Belinda, but it’s saying it’s by Ellie.
How can I change it?