My advice is to consult an Orthodontist. It is possible to get partial braces, or just braces on your upper teeth. I also had a bit of a gap between my 2 front teeth and it only took a few weeks for it to close completely. I wear mine for 20 months however, because of jaw problems. You will have to wear a retainer afterwards otherwise your teeth may go back to their original position.
An Orthodontist is someone that will give you Braces if you need them but if you're a sister/brother that needs Braces and you think you do to then smile a lot and and try and make them notice but don't say anything!