Thats because someone who didnt know the lore wrote the dialogue for Warmind🤦🏼‍♂️

The story goes that she was her human sister back in the golden age. Elsie and Ana were part of the Bray family and worked at Braytech. Elsie discovered the darkness and took measures to fight against it. She had invented some weapons like Polaris Lance. At the time Braytech had developed Exo's and moving human conciousness to exos. Elsie bray had moved her conciousness to an exo and used time travel to meet us in the future. Apparently she had discovered time travel via Vex artifacts or something. Ana Bray just so happens to be revived as a guardian on Mars when we find her. Most guardians do not know their previous life but Ana being on Mars and her family name plastered everywhere, she remembers who she is. Especially when Rasputin welcomes her home. This is from my memory, could be twisted but Im sure some keyboard warriors will straighten it out.