It's not too late to start a new career - she is young enough.

But she needs to keep in mind that it will dampen her career chances somewhat - her peers who had an "early start" will be her seniors at work, and she'll have slightly less time (long-term) to achieve her career goals. But if she's confident about her choice, I think she should go for it. Your friend still has decades of active life left, better to spend it doing something she likes.