At some point she decided that enough was enough, that since you obviously don't care about her anymore she's just going to move on. Easier said than done I suppose, because at the end of the day she's staring out the window with tears on her cheeks. She's tired of being the woman who loves you with everything she has, but yet you give nothing in return. She stayed by your side long after she knew that she wasn't suppose to be there anymore...and for that, she takes responsibility, that was her fault. But your mistake was letting a good woman go, and it will eat you alive to see her be great to another man!
She spent so many years loving you in hopes that one day you would wake up and see the good woman standing in front of you. She went above and beyond for you, yet you made her feel like she was never enough. She spent so many nights alone crying wishing you'd change. That's when she realized she was with the wrong man, because she shouldn't have to wish. Love is as love does and she realized all you were doing was hurting her. She got tired of being hurt, lied to, cheated on, and disrespected. Her heart finally gave in and let go, not because she stopped loving you but because she got tired of hurting and realizing that she'll never find the right man if she is still holding on to you.
One morning she woke up different. Done with trying to figure you out. She realized that loyalty wasn’t a word but a lifestyle, that life is way too short to leave the key to her happiness in your pocket. She started spending time with people who love her unconditionally and stopped wasting her time on you who only loved her when the conditions were right for you. She can't promise she'll be ok without you. All she knows is that she'll be better off than she is with you. You drain her and she just can't live like that anymore. She wants to feel free, she wants to feel happy, and she wants to feel peace in her heart. If you or anyone else can't give her that, then she'll give it to herself.
