Will they give back her revenues after 3months?
If your friend reads the Terms of Service at the bottom of the Fiverr main page they will find the rules as to how Fiverr works including the answer to this question.
Everything is explained there in great detail.
Fiverr is only going to make those funds available that were earned by offering legitimate products/services (that abide by Fiverr’s ToS).
They are probably not going to make revenue that was earned by offering products/services that go against the ToS available to your friend for withdrawal.