Plant structure is controlled purely by genetics and there is little you can do to change this, except growing her with inadequate light to increase stretching, but you will end up with weak and spindly growth. Tight internodes generally lead to dense chunky buds anyhow, so I would be just allowing her to do her thing.
Cheers, Organoman.
P.S. - two plants in one pot is never a good idea, they will just compete for everything, especially root room.