Your sister-in-law and daughter are truly people of great character

Even though they kept babbling and hurling profanities,
the sister-in-law endured it all and responded politely using formal language.
Even when called a "fucking bitch," she didn't respond with insults.
If I were in her position, I don't think I could have even gotten out of bed from the extreme stress.
The way she handled the phone call with the lady and her niece was truly impressive.