From the CBC via the AV Club. She was 63.

I own and appreciate a couple of Kate & Anna McGarrigle records... I think I really like them because they remind me of a time when I was small, when my parents would sometimes bring me to living-room folk concerts... a time of beards and scratchy sweaters, houses filled with books, food, and friendly strangers.

I guess I will better remember her, though, as the one-time wife of Loudon Wainwright III (and the mother of Rufus and Martha Wainwright) and the subject (directly or implied) of so many of his songs. From devastating chronicles of their epic fights like "Red Guitar" or "Your Mother and I" to tales of times better spent like "Dilated to Meet You" or "Heaven and Mud" to shocking kiss-offs like "Whatever Happened to Us?", I felt a startling emotional intimacy with their relationship. The rawness of lyrics like this one from "Pretty Little Martha" still affect me: You're in Quebec, with your mother / and I'm down here in New York state / life is cruel and so is fate / life is cruel and so is Kate...

Go sweetly, lady. For all the hurtful things Loudon sang about you, you seemed like nothing so much as a human being.

Used to have a red guitar
‘Til I smashed it drunk one night
Smashed it in the classic form
As Peter Townshend might
Threw it in the fireplace
Left it there a while
Kate, she started crying when she saw my sorry smile

Red guitar was made of wood
It could not take the heat
Red guitar, it caught on fire
And the damage was complete
It burned until all that was left
Were six pegs and six strings
Kate she said, “You are a fool;
You've done a foolish thing.”

I placed the remains in the case and I put the case away
Went to New York City for a new guitar the next day
I bought myself a blond guitar
Had it for three days
Some junkie stole my blond guitar...
God works in wondrous ways.