The Red Family/Inherited Obligation model offers an insight here: people put up with an Inherited Obligation family because they expect to get their own chance to be top of the heap. It sounds like OES isn't going to last long enough to give you that.

You might want to step back and look at OES from the viewpoint of Negotiated Commitment instead. From that point of view, it seems to me as if they're breaking their commitments to you: you've supported them, but they aren't supporting you when you need them.