Big Sister x Little Brother Marriage roleplay

You'd be playing a big sister who is deeply in love with your little brother. This stems from an age gap between you two which caused you to become a semi co-parent from a young age(like 10 0r 12). One day you decide you want to marry your little brother and through the internet finds someone who'd be willing to do it. You convince your little brother this is a good idea and the two of you runaway together. 

If you'd like to do this roleplay you must be able to provide a character description(or I can make one for you) and be willing to play female. It doesn't matter what you identify in real life. All are welcome.