Here is my 14-week old Buff Orpington. She/he has had the red comb for a few weeks now and my other BO still has a pink/white comb.
Pretty sure I know the answer here but she/he is my favourite and these are my first chickens so I want to be sure before going to craigslist.
A profile shot of the bird standing on it's own is best for sexing. I may be seeing some saddle feathers, but it's really hard to tell. This is the age when the girls start getting larger, redder combs, it's an indicator of sexual maturity and readiness to lay. So that's not a good indicator of age. Overall, I'm thinking pullet.
I think you may have a pullet there. Male Orpingtons develop their combs pretty early on and they do grow fast. So your baby, being only 14 weeks old looks to me like a pullet. Having a red comb at 3 months does not necessarily mean rooster. In another 5 or 6 weeks, she may be laying eggs and many girls have red combs long before they lay. I would hang on to her/he as I think he is a she!
I'm 90% sure you have a pullet, assuming she's 14 weeks old. My Buff Orp roosters had combs like hers at only 7 weeks old. I would definitely hold onto her for at least another 2 weeks, by then you can be sure.
Like someone else said, a good profile pic would help.