What she means:
"I will protect Altlivia Dunham til the day I die and sit the fuck down and I'll tell you why. She was convinced to believe from the start that the other universe deliberately started the destruction of her universe and were set out to destroy it. Also she was convinced to believe that it was her universe or theirs (when that wasn't true). So when she went on her mission on the other side she went with that mindset and saw them as her enemy. I'll admit she did some shitty things when she was undercover as our Olivia, but she had to do what she had to do to complete the mission. They were her orders. Not only that, but she was constantly trying to prove to Newton and even herself that she was able to pull it off. Let's just say as well; she had no idea how they were treating Olivia while she was captured on the other side and had no say in what happened to her. She had to cheat on her boyfriend with Peter so that she could keep her cover and complete her mission. Spending time over on this side she started to realise that these people weren't the people she thought they would be. That they weren't her enemy. After getting back to her own universe she discovered she was pregnant with Peters' child and for that she then lost her boyfriend (now fiancé). Being a carrier of the virus VPE it would mean she and the baby would not make it through childbirth (just like her sister did) she knew she would have to rid of the child, but before she could give it much thought she was kidnapped and her pregnancy was accelerated. Altlivia fucking Dunham while heavily pregnant then managed to kick ass and escape and then gave birth in a Chinese restaurant and luckily because of the accelerated pregnancy the virus didn't have time to replicate as fast as the pregnancy. Then after the activation of the machine by Walternate Altlivia risked her own life and risked never seeing her own son again so that she could go to the other universe and attempt to save both universes. When the timeline got reset her son was erased from existence and she had no idea. No idea that she had a child and now he was just gone. Then in this new timeline she lost her partner and we saw a side of her that we have never seen before. You could see how devastated she was by the loss. She was so determined to find out and bring to justice whom ever was responsible. While talking to Lincoln about how her world was healing because of the two universes working together, you could see on her face how happy she was and you can see how much she cares in the whole scene between her and Olivia when she is telling her about imagining the people on her side seeing rainbows again. You watch all of that and come back to me and tell me that she doesn't care. If you simply hate on Altlivia because she 'got in the way' of Peter and Olivia then you can actually fuck off. If you ever come for Altlivia you can go through me first because I will protect her til the day I die."