you have to ask if you over watered it? gave her too much fertilizer? did she go through heat stress? possible wind burn? one of these is the answer. my guess is she is a picky eater as the others look fine, and your are like what f ? is going on. your leaves are canoeing up. the plant is good minus the signs of what happened. it happens from time to time. i pick these off. they just make me think what happen.
what your seeing is how the plant deals with stress by trying to suck out what ever energy from that leaf.
i say pick off the ugly and keep your eyes open , she does look really nice so far for you.