theres only one year difference! Your both a legal age…you love each other thats the main thing right? i have a two year old baby brother but as much as i love the little fellow if i could spend every day with my man and get married with him with just his parents being alright i could do it! if you truthfully love him than go for it your family will always be there for you your little sis will deff want to stay in touch just make sure you dont miss too much of her growing up and make the send pics! they cant do anything once your married can they? So i say go for it…well follow your heart! hope i helped good luck love xxxxxxx