Never Let Me Go {a Carl Grimes fanfiction}

Coming from a different universe, Megan-shown as a female Negan, and the daughter of Negan- came crawling to find Rick Grimes. Bleeding and broken, she had tears in her eyes when the leader of the group carried her inside and got her healed up. Barely surviving, Megan manages to stay alive.
With pain growing in her body more and more every day, she was having to work and earn her keep to prove that she was not going to throw Rick under the bus, and let him get killed. However, in the midst of everything, Megan found someone that may actually give a shit about her.
The son of the leader, Carl Grimes, kept giving her the easy end of the stick, and giving her a chance in the world. He was babying her when she was injured, holding her when she was scared, and helping her learn and grow back into the Walker Fighting shape she was once in.
A bond being formed, Carl and Megan became one of the finest things and couples that lived. Regaining her memory more and more, it reveals that Carl and Megan once had a past, and a little more than that.
What is it that these memories will reveal, and how will the bond of Carl and Megan grow to form a better love story than Twilight?