<human>: Can you summarize the given text in a few sentences?

So I have been friends with my SO for about 6 years, but we lived in different countries and just exchanged messages/email, but we recently got together as a couple. This issue with her sister has been ongoing since before we got together; and my information is strictly from my SO.

In the early part of this year, the BIL had a death in the family and as the only capable adult male in the family had to step up to manage things ( in a very patriarchal community), and the sister seems to have been a little upset by the lack of attention from her husband, whatever the case, that relationship was strained, and apparently the issue of divorce/separation was raised.

They live in a fairly conservative community, and divorce is still not great for a woman; my SO told her parents about it, hoping that they would intercede. And they did; they are pretty reasonable people so I imagine they would have been supportive either way, but would have urged a degree of caution before leaping into a divorce. 

The sister got upset with my SO for involving their parents, and has stopped speaking to her. I sympathise with the sister, I wouldn't want other people (even my parents) involved in my relationship unless I sought counsel from them, or if divorce lawyers had been contacted etc...not just based on the threat of divorce. I think she was a bit embarrassed by it all; however this was over 5 months ago, and the cold-shouldering is still ongoing. The BIL is collateral damage, since he does respond to messages etc...

It has really affected my SO, I think she was expecting a month or so of this, not so many months with no apparent end in sight. I am not sure how to advise her, or what she should do...
<bot>: My SOs sister has basically cut her off, after my SO told her parents that her sister and husband were considering a divorce.