Through experience you comes maturity right? ... but that doesnt mean you have to have a certain amount of maturity at certain ages. So many young people are more mature than so many older people already!
A person dont have to do all the mistakes itself... it can learn from other people's mistakes too! We study the right methods in physics and avoid errors... these errors were made by the theories inventors... and they learnt alot from those...but wrote down how to tackle the situations....or about their life.... so we learnt to go ahead from that point forwards!
I am involved with a EAST ASIAN girl! ... I dont usually share it...its personal....but you should know that it was difficult in family, specially with mom! But after alot of convincing, she finally is happy for me and her.
They (the parents) cannot trust the outsider! Its natural, they are concerned for your life...they want your good...and they dont want you to be involved in any PUPPY LOVE. But if you can convince them about your confidence in the relationship...with logic and proove that it is the right thing for you...and she is the right person....then if your parents love you, they will agree. But if they are extremist, and love their ideologies more than you....then you can say that 'they are wrong'. But you must give then the respect... offer them the care and explanation! They deserve it.
Hope this makes sense

.