But she had not yet responded -- until now.
Jenner sent out a tweet wishing her life was easier, which opened her up to a barrage of Twitter backlash from Cobain and the Twitter hivemind. Critics called her "self-involved" and "ungrateful."
Jenner has been in the limelight for some time from her reality-TV stardom in the "Kardashians" franchise and subsequent modeling career. Jenner is a 17-year-old whose 17-year-old problems are on display for the world.
The tweet got to Cobain in particular, who said "i'd rather be a scumbag than a [expletive] idiot." Cobain further left a stream of what she said Jenner's problems rank below: "oh ya, not to mention, CANCER, famine, poverty, draught, disease, natural disasters, Death."
Jenner came back with a response today, asking why Cobain, 20, is in a place to judge her.
"I am aware that I am very privileged and blessed, and i'm thankful for that everyday, i know there are greater problems in the world," Jenner tweeted.
"I pray for those people every night and give back as much as i can. so who are u to judge me?"
She ended the feud for now, leaving Cobain with "an individual's feelings are relative to their environment. you don't know me, you don't even know what I was referring to."
Cobain has not yet responded.