Something so small like 14 or 12 will make no difference to me. I don't think anyone would even tell that you had stretched ears. The two guys who answered probably don't know what size your talking about. There's no way you can say that 12 gauge ears are any uglier than a regular piercing. The hole is only 2 millimeters in diameter compared to a regular piercing which is 1millimeter. I actually think its pretty hot for a girl to have stretched ears to 0, or 00, but I don't like them much bigger than that.
yeah you can't even tell when they are that small. even a 14 is relatively small. my girlfriend had 0 gauged ear lobes and they weren't ugly at all they were kind of cute after I got used to them and honestly at first I really didn't like them. I feel like guys, obviously not all of them, are a little intimidated by a girl who would gauge their ears or something different like that and guys label it as "unattractive". I don't mind it so much anymore even though she let them close up but yeah I wouldn't suggest stretching your cartilage...that would be a little extreme
I have a 000ga, guys don't seem to mind. Stretched cartilage piercings aren't something you see every day though, dermal punching is safer in that respect. I don't reconmend you stretch your cartilage DIY, especially if you have no experience with stretching whatsoever.
12 or 14ga is quite small, I don't think anyone would notice.