@OmSigDAVID,
re sis and the drama... my response to the previous few posts:
Yes, he was demonstrating his devotion and commitment to her which, if taken as an isolated incident, is not all that troublesome. That's the problem with isolated incidents. Taken alone they don't paint a very clear picture. Taken in total, the picture is a different thing altogether.
I agree with eoe that showing up at her workplace in drag (ok, kidding) isn't all that alarming on it's own. But I definitely agree with buttrflynet that a puzzle is a sum of it's parts and the "just make sure..." warning is apropos.
As to a restraining order... there's nothing here yet that would result in a restraining order even if she wanted one, which I'm assuming she doesn't. One simply doesn't march into a courthouse and demand a restraining order. There are definitive criteria that need to be met in getting even a temporary restraining order, be it from a domestic violence (not here) or civil harassment (not yet) standpoint. The problem with throwing out "get a restraining order" or "take it to the authorities" is that that only becomes an outlet AFTER an unlawful act has been committed.
Those who prey on the good nature or fear of others know precisely what they are doing. I don't know the potential BIL in any way, shape, or manner but taking a collection of isolated incidents into an overall perspective is not a bad thing.