At what age should a girl start dating?

I wouldn't say that there is a set age or an expiration date when it comes to dating. It generally depends on circumstances, maturity, and set of minds.

You could be 13, 16, 20 or even 30 - if you feel like you are ready then why shouldn't you do it? 

You shouldn't feel like it is something that is socially imposed on you. If all you friends start dating, it doesn't mean you should do it too only because they're doing it. Similarly, just because they don't do it it doesn't mean you shouldn't.

If you meet a person who shows respect, affection and understanding - and if this feeling is mutual! - then I don't see why you shouldn't date.

I think the major problem here is that people link dating as being sexual. The two are not the same thing, you could date a person without falling into sexuality or intimacy too quickly. You could spend time together holding hands, doing something you both love, going to the movies, meeting up with friends and so on.

Obviously you might find resistance from your parents if you are too young (let's say 12) and I think that is normal because this does not generally happen really easily and they might be afraid the relationship might become intimate, you could do something you might end up regretting and it could take time away from things like school, personal development and so on.

However, I think relationships are part of personal develpoment too, and you could date someone while keeping your individuality, going school too and getting good grades. It is just a matter of balance and I'm sure that if you're willing enough there really shouldn't be major issues.

Either way, don't put too much pressure on yourself and do what you think comes most naturally to you.

Best of luck!