Classic blaxploitation movie starring Pam Grier
Black Mama, White Mama
(1972)

Lee Daniels (Pam Grier) and Karen Brent (Margaret Markov) escape custody from the Women's Rehabilitation Camp while on a bus ride to be interrogated.  Chained together by the wrists, they flee into the countryside. Lee Daniels wants to get to a boat that's waiting to take her off the island but Karen wants to find her Guerrilla friends and fight in a revolution.

The women and the revolutionaries eventually run into each other about 9/10s of the way through the movie; the chain is cut and they take Lee to the boat.  A gun fight breaks out, Lee gets on the boat and watches as Karen gets hit by shrapnel and is killed.

Thanks Ed!