She is acting submissive because she was just introduced into the tank. He is acting dominent because it is his tank. The devider was agood idea but honestly 85 gallons is no where near enough for those two together. At 4.5" she is just comming into her own as far as agression goes. I would proceed with extreem caution. Good luck with them.
I'll keep them closely watched and if i see this cannot work out I'll sell one of them....Sometimes you cant have everything you want in life I guess...