“My feeling is that if a 7 year old was capable of this behaviour he would continue forever, not quit after a couple of years.”
He quit raping HER after a couple years. Then moved on to his next victim. Most likely someone younger than she.
Not always... Not all children who behave in that manner end up being abusers forever. It is much different than dealing with someone who is a teenager, or even someone who is 11yo. There ARE still some who can respond positively to intense therapy at those ages provided they are not people already suffering from devastating mental illnesses.