Oompa, everyone is welcome to their opinion. Yours is as valid as any.
NOT IGNORING this is feeding the beast. They want Jeff and company to get upset
and think about why they are being shunned. While you may have some point that
they won't know that they didn't get a rise out of Jeff, they will not see the reaction they
hope for. Therefore, ignoring this could be a better outcome than giving in to reacting.
Also, they may know very well from the source that tells Jeff. They may know that
he knew about the visit.
Focus on helping Jeff here. If not ignoring his sister-in-law, what would you suggest?
Why do you suggest that?