There are some translations done, depending on what language you need. Also, if you want to start a new one, I will get you the pot file. Contact me if this is what you need.
If you are using a translation file for the plugin already, to get the fields properly translated, you need to force a reinstall as the fields are stored in the database. So, if you have loaded the plugin at anytime before you added the translation, the field names are already loaded into the database. These need to be deleted in order for the translated field names to be loaded in. There are two ways to do this. (1) you can deactivate the plugin, then use the delete feature in the WP plugin admin. This runs the plugin’s delete feature which clears out the database settings. Or (2) there is a toggle in the wp-members-install.php file called $chk_force. There are instructions on using this commented into the file, but essentially, setting this to true will force the plugin deactivation/reactivation to reload all of the plugin’s db options (thereby providing you with translated field names). Just be sure to set this back to false when you are done, in case you deactivate the plugin later and don’t want to unintentionally override any custom settings.
Alternatively, if you are not going to do a localization of the plugin, then you could translate the field names in the install file and reinstall. But you will still need to force these settings into the database using one of the above mentioned processes.