That is possible and would also explain Jill and Bella's friendship. Interesting thought.
What if Isabella had a thing with Lana. Then a James came along and they had a three-way relationship. A little later, Lana passed away. Isabella and James get married. A few years later, Jill comes to B&R.
There is a strong hint in EP5 that something happened between Jill and Isabella. But given the possible past as described above, James could have freaked out.
There are so many theories about the room that I prefer to be surprised. I don't really care either.