In my own thoughts, I was a little hard on her when this case broke ....but after reading her earlier posts - I can see how she might have truly believed MG was innocent. She obviously latched on to someone that may have not been ready or capable of a healthy relationship. Instead of accepting that- she tried to fix it. MG probably pushed her away numerous times either through his actions or inability to quit his bad habits . Based on her writings, it sounded like she kept coming back. If only she walked away.
She was probably happy as could be packing to move into that trailer. The conditions may have been secondary to her because she had her little family all together and she'd make it a home. I can see her thinking that she would work and get them out of there. MG would turn the corner and get a job and life would be good. (ALL of my own assumptions here but, like you ,I think that's why she could whole heartedly support MG). She was clinging to that dream and hope. This could be her first love so that's why I was wondering if any articles mentioned how long they had a relationship. She probably is shattered losing her baby and MG. I have to remind myself - she is a teenager. I could also believe that Ember's existence may have been a result of trying to get MG to change .
I do hope she had adult guidance trying to steer her correctly but at that age - the more parents push the more kids tend to rebel.