Will removing this plugin change the login link?

I’m trying to improve the sites speed, so some plugins may have to be removed. To login to the site, you have to go to a different extension instead of the usual /wp-admin extension. I’m afraid to remove Theme My Login because I wasnt sure what was causing this login change. Does Theme My Login have this capability, and if so, how do I check?Thank you for any suggestions.

The page I need help with: [log in to see the link]