NTA but not for the reasons others have stated.

This might be a controversial opinion but I believe he has a point on wanting to have a special gift for his two sons that only the 3 of them can share. He is not the asshole for that one.

What he is the asshole for, is not willing to talk with your daughter to understand how she feels. The right thing to do here is to wait until your daughter becomes 18 (not because there is an age barrier, just for sentimental value about getting into adulthood) and then gifting something equally special to her. Not a watch, so again it is something that only the two of them can share.

I believe the point of this is not just to rule an online decision, but to actually fix the situation you are facing.

I say, have yet another talk with your husband. Again, let me say that I know that you are in the right for this completely, but in order to fix the situation, I suggest starting out by acknowledging his desire to have something special only between him and your sons. This is not you saying that he is guilt-free, rather you trying to find common ground to make him understand. Then say that he should plan something for your daughter, perhaps when she is also older. An alternative would be for you to do it to your daughter, though I believe that this can not be done now because it will feel like your husband just gave up on the daughter and you decided to ease the wound. Finish by saying that he MUST go and talk to your daughter about how she feels and hear her troubles.

Your words read like a very understanding and thoughtful person who really wants the best out of this situation and I hope you do whatever you deem correct.