This was relayed to me secondhand via Eagle (DF). Niece is the daughter of his brother (FBIL) and BIL's wife (FSIL). FSIL wants our advice because she knows I read E-Hell and because we are removed from the situation yet close enough to care about our Niece (her words).
Niece will be 2 in April and, since she first started growing hair, has had what we like to call Einstein Hair: it is all over the place and untamable. Within the last 6 months or so, it has finally grown long enough that it, for the most part, lies flat. FBIL and FSIL were finally over the frustration of her having unruly hair...or so they thought.
Just before Christmas, FBIL and FSIL dropped off Niece at her Grandma's (not my FMIL, but SIL's mom) for a fun day. When they returned to pick up her that evening they discovered that Niece's bangs had been cut. FBIL asked Grandma who cut Niece's hair; Grandma said it wasn't cut, that it had always looked like that. FBIL again insisted for an answer to his question. Grandma denied it, said that she hadn't cut Niece's hair and that it had always looked like that. FBIL, FSIL, and Niece immediately left.
I don't know how much time passed between events, but Grandma called her other daughter and confessed to having cut Niece's bangs. Other Daughter called her sister (FSIL) and told her that their mother said she had cut Niece's bangs. Now Grandpa is demanding an apology from FBIL for the way he treated Grandma*. FBIL refuses to apologize (I think rightfully so).
The question is, how do they proceed from here? FSIL wants to maintain a relationship with her parents but she is furious. I'm pretty sure FBIL is still so angry that he doesn't even want to think about them or about resuming a relationship with them. FSIL doesn't know how to tell them that they erred (big time!) and that she can't trust them to watch their daughter until they can rebuild that trust. She wants to write a letter but doesn't know if that will be PA or if she should just do it in person. Any suggestions?
ETA: the reason for the *.
*The Eagle and I don't know what FBIL said to Grandma, but it was probably direct and upset language (not swearing or anything, but rightfully upset/angry and telling Grandma so).