In this episode, Jill disclosed the case to the news media without authorization, which made the BAU team very passive. Rosie used these words to warn her to pay the price for her "ambition" because she was the same before.

The quotation is from "Anne of Green Gables"

Chapter 36 The Glory and the Dream

CHAPTER XXXVI The Glory and the Dream

Original text:

For we pay a price for everything we get or take in this world; and although ambitions are well worth having, they are not to be cheaply won, but exact their dues of work and self- denial, anxiety and discouragement.

What it wants to express is: if you want to get something, you must pay the price. It is a good thing to be ambitious, but the road to your ideal is not smooth. This kind of hard work is closely accompanied by uneasiness and disappointment.