Age of Consent and Statutory Rape in Illinois

My question involves criminal law for the state of: Illinois

I have a former supervisor who shared his troubles with me. He told me that his 15 year old daughter was going behind his and his wife's back and seeing a 19 year old boy. She ended up pregnant at the age of 15. He's 19. My friend took this to the courts yet they dismissed the case because it was "consensual". As me and him both are under the impression that the legal age of consent is 17 in Illinois. How is it that a 15 year old can consent to sex if the law clearly states you have to be 17 to consent? especially after she ended up pregnant and dropped out of school. Can someone please explain it to us? Thanks!

Because for victims between 13 and 17, there is a 5 year "Romeo and Juliet" clause in the sex crimes statutes in Illinois. He'd have to be 20 before criminal charges would be successful in a case of otherwise consensual sex.

They tried to change the minimum age to 14 with a 4 year span in 2011, but the legislation didn't pass.