Helping kids develop a vocabulary for their emotions... nuanced, with degrees of intensity... can be helpful in getting them to "use their words" rather than over-emoting.
Does she read? Reading books about similar situations can provide bibliotherapy, helping a child see their situation within the pages of a book they are reading. Kids may find circumstances which parallel their own life and develop the specialized vocabulary to describe a range of feelings.
The Berenstain Bears is one example of a series which touches on positive behavior and character development for young children, as they follow the antics of this lovable bear family.
Gifted Kids' Survival Guide for gifted kids under age 10 is one idea... at her age you may wish to pick-and-choose pages or topics to read to her and discuss with her.
The book
F is for Feelings or
Feelings In A Jar may be a conversation starter for some parents and children.
Hoagies Gifted Education Page has a great
reading list.
Some of my best friends are books is a helpful guide.
