Very thoughtful read Suma <3
I think your sis in law just didn't comprehend the seriousness of her mother's condition considering she is so shaken by it..
Also, though a tale of most Indian families, it struck me as a little annoying that somebody else had a say in what career you should pursue.
I think apologies come when the person has meant something to you, it is that simple.
I recently went through something that made me realize that some people have an ego so huge or have done something so damaging that they rather lose you than apologize and course correct. Apologizing is akin to accepting that they had a part to play in the mess, and they rather not do that. There is a lot at stake and sometimes that coveted image of a thorough gentle gentleman to maintain. I do not understand how some people I have encountered claim to be gentle and at the same time have done something deeply damaging to an other person. Such a massive dissonance in their personality that they can almost gaslight you into believing that you are the problem. If they apologized all of it would come crashing down like a pile of cards, a spectacle for the world to behold, so they rather keep up the charade..