No worries. Our subscriptions are for all sites you own. If you're a developer or, if perhaps you had dozens of sites, we'd ask for more than one subscription. Otherwise, usually the issues are related for a user between all their sites.
As for what you describe, the gender field is part of the user's public profile. A lot of other fields need an additional permission from the user to allow your app to see it. You also need to get Facebook's approval to be able to actually request those permissions from your users.
On your site above, I see that you are requesting the following permissions:
email,publish_actions,public_profile,user_religion_politics,user_about_me,user_birthday,user_hometown
When I try to register with Facebook, I'm only asked the following:
Solteras Cristianas will receive the following info: your public profile and email address.
It looks like you haven't gone through the review process for the remaining fields you want. Please go to the
Facebook Developer Area
, click into your app and go to "Status & Review". In there, you can request permissions for the other fields and give a brief explanation of how you'll use them.
I hope that helps explain,
Alex