I would take the opposite view- Biddy is a very normal, though late middle-aged female and shows proper respect to males. She has had three previous adult male partners(four if you include 'Joe' in the past) and got on well with all of them, and she took to Boulas immediately. There may be scuffles initially but I would expect her integration to go smoothly otherwise.
I took the discussion on the thread perhaps to literally!
I did think the frequent moving back and forth was not helping her case much ... Was management of the gorillas this jittery?
In normal gorilla integration process(es) a new gorilla will be "tested" by the female cohorts to determine rank and the silverback will exert is position pretty much from moment zero/go. One would expect scuffles to happen initially and weathering out over a short period of time when the new ranking system of the entire group has been set.