This is Naya Rivera. She is 25 years old. I think she would make the perfect Johanna because she looks just like the description. You may remember her from Glee as Santana.
Johanna is a past victor from district 7. Who at the beginning acted shy and slow but when she got in the game she surprise all with her rage and skill. She's deadly accurate with an axe and is described as having spiky hair and wide-set brown eyes.Her favorite weapon is the axe, since District 7 is known for lumber.
During the Quarter Quel Johanna brings Wiress and Beetee to Katniss to show she is on her side. She endures the terrible blood rain in one of the hours in the games.