Have you taken any classes with her, obedience classes or anything that had you working just with her on a more intensive or one-to-one basis? That's the main thing that comes to mind as a way to start building a relationship that may not be there. Even if you've taken classes before and she already knows all the appropriate commands, taking her someplace that only you and she go to and then spending time practicing whatever you're supposed to practice might spark a flame. If there are classes like rally or something a bit up from basic obedience, that might be fun.
Our older dog, who was an "only child" for several years, doesn't always get up to greet us at the door, me usually, my husband, rarely. He also is excited to go out if he thinks we're going someplace, especially if he's seen suitcases being loaded into the car. He just has never been a cuddly, best friend kind of a boy, always a bit aloof. Maybe that's just Corina's natural personality and she'll never really fill the same role that Heidi did. It may not have been as apparent as long as Heidi was there to play the light of your life role. I'd try classes or taking her for walks or hikes or adventures that only the 2 of you go on, without the other 2 dogs present.