In the feature, the magazine said that her Kylie Cosmetics company has amassed $900 million.
People thought that calling her "self-made" was misleading.
And are asking if Forbes know what "self-made" means.
Author Roxane Gay said, "Her success is commendable but it comes by virtue of her privilege."
But people also gave credit to Jenner.
And think her hustle is smart.
Kylie's sister Kim retweeted a tweet defending criticism.
A spokesperson for Forbes told BuzzFeed News that members on the Forbes 400 are given a score from 1 to 10 to capture the variations of how self-made a person is.
The spokesperson said: "Forbes fully acknowledges that within the term "self-made" there are many who are more self-made than others.
"In fact we began scoring members of the Forbes 400 on a scale of 1 to 10 to capture the variations.
"Yes, Kylie comes from a wealthy family and she got a visibility boost from her family but she owns her company and is valued based on earnings she has personally received and on the value of the company she founded."