Your mom was way out of line, acting like an insolent child ON your brother's birthday!

Yes she works hard, but a paycheque does not a parent make.
She should chill the fk out and put the needs of her kids first!
eg. My deceased dad and niece share a birthday, do you think my sister mopes about the entire day? NO! she goes out of her way to make Krishana's birthday feel like a real birthday, even though she wants to cry all day for dad.

Ugh, you're mother needs to grow up, she's infuriating and I dont even know the woman.
Yoga would definitly be beneficial for her.