I'd suggest rather than reading make her listen to people talk. For example, she will learn more watching news or talk shows..watch comedy shows on youtube like =3 or stand up comedies to understand the humor here..she also watch the family shows like 'Everybody loves Raymond' and other shows like that..I don't recall many names becuase I don't watch it much myself..also, if you hand out with your english-speaking friends; take her with you too..If you work in a place where you have to talk with customers; take her with you too..she can stand aside and observe and learn...

I would add more tips if I can think of and I ask fellow Sajha followers to add more.

All the best!
Thank you!