this is quite possible, some times J,k rowling mkes resemblances in the story like this, to make you think. I have noticed this about ginny and lily but there is one crucial difference between ginny and lily and harry and james. Ginny always loved harry even after she started dating other men, lily however only loved james after he stoped being a showoffy jerk. Harry unlike his father never had a big head about himself, he never went around shoing everyone how cool he awas