Is my friend rude or am I just sensitive?

Okay, so my friend, let's call him/her J, has been making me feel like she wants attention. We carpool to school with a couple of other girls, and I complimented this other friend, let's call her N, on her eyes. They're a really pretty hazel color, and then J says, "I mean, they're not really special. They're actually light brown." This honestly annoys me. Apparently none of my other friends noticed it. We're in the school band, J, N, and I. N has a smaller instrument, I have a French horn, and J has a sax. This other girl we carpool with, K, isn't in band. Since they have less stuff to carry, they usually carry our stuff to help. I was struggling the other day to carry it, and N was really nice and helped me. But she was also carrying J's saxophone, so they were struggling. I offered to carry one, so I asked her which one was heavier so that I could take it. J decides to cut in and say, "The sax is WAY heavier than your horn, trust me, it's not special." For reference, saxophones and their cases are about 15 pounds, while a French horn from my school band is around 20. I'm not saying she doesn't have a lot to carry, but I wasn't trying to compete, I was just trying to help and she made it into her sympathy party. No one else other than my dad when he was driving us really noticed it. I explained it to my friends, and they agreed that they did say that. I explained to them how they see it, but I feel like they're not as annoyed by it as I am. So am I being sensitive or is J actually doing something wrong? I don't mean like horrible, I mean am I just imagining it, or is it actually something there?