yes, I know what you mean "she wears her heart on her sleeve" - I had to look that one up myself ;-)

"wear one's heart on one's sleeve. and have one's heart on one's sleeve. Fig. to display one's feelings openly and habitually, rather than keep them private. John always has his heart on his sleeve so that everyone knows how he feels. Because she wears her heart on her sleeve, it's easy to hurt her feelings."