Are older girl and younger guy relationships ok?

I am wondering if they are because I am interested in girls older than I am (I'm almost 15) and I'm not even sure what it is. Older girls (around one and a half years older or a little more) seem more mature, have their heads on straighter (figuratively speaking), they're more like actual women (and not like little girls), they are more physically and emotionally developed, and a lot of other things, whereas younger girls (lets say, anywhere from 11 to my age) don't appeal to me at all. So if I could have an answer to whether this is ok that would be great. Thanks!