The speaker in "Making a Fist" is the 7 year old girl who was traveling with her mother, now all grown up.
The poem begins with the speaker remembering when she had been traveling for days with her mother. She was unsure if she would survive the journey and asked her mother "How do you know if you are going to die?". Her mother replied simply, "When you can no longer make a fist." The poem then continues with the speaker mentioning all of the obstacles she has overcome. She keeps opening and closing her hand because she is still alive; she can still make a fist. She has overcome.