I am so happy for you and your difficult child!
My difficult child just started his first job a couple months ago and it was a nerve wracking process for me. lol It has really helped him in so many ways. He is maturing and understanding the value of money. He is confident and learning to socialize outside of his typical circle. He is happy and the added activity level has helped his moods. It really has made such a difference in all of our lives.
Having decent and kind people to work for has been pivotal so I really hope your difficult child's employers are nice. She is well on her way to success. Taking the inititative to find and secure her own job in "secret" takes a level of maturity. Good for her!!