You say she will have a melt down if she messes up. Makes sense to me. Remember these gifted kids are HIGHLY perfectionistic and will have a hard time tolerating failure.
It may even get to the point where they will not even TRY doing something they know they won't master immediately. With DS4 I try to encourage the fact that he is TRYING and if he does something well I compliment the EFFORT. I actually never tell him that he is smart and don't like when others do either. I feel it will set this high standard in his mind to ALWAYS be smart and make him not want to do something unless he knows he can do it. I will say instead "Wow, that is great! You tried really hard to do that and look what you did! Wonderful!"

Seems it takes a bit of the pressure to perform perfectly away. I will tell him that as long as he tries hard, that is all he can do. Sometimes it works, sometimes it doesn't.

DAD22, this whole thing about counting objects. I didn't know they are not "supposed" to do this until age 3. DS is 23 months and just counted 9 toy cars correctly yesterday. Interesting.