I imagine that Jane secretly mourns her sister, but can’t show it because she’s a big ole baddy. Also has a complex because she worries that her sister could have done more for the na’vi than she can.

Also in this AU I imagine that two twins growing up on overpopulated earth, Tanya was the one who inherited a love for science and human betterment which would give her more opportunities and a chance to leave the slum areas they lived. Jane was the hard head who got in fights with kids in the ally and failed school, whose only real choice was to join the military.