I need advice. I’m not exactly sure how to feel about this...

So my friend, used to be best friend but for reasons I just don’t feel like she deserves that title anymore. She hasn’t been the best of friend these past 3 years. Anyways she works for a fast food restaurant, I wasn’t recently working but decided my family needs two incomes. So she invited me to come apply. I already knew the GM so I knew I would get the job. I’ve been working there for about a month now. I was hired as a shift leader. (I have lots of previous experience, especially in management) anyways it turns out the GM was looking for another assistant. He seen the way I work and he’s decided to make me his assistant (unknown to anyone at this moment) I become his assistant on the 17th of September, and get a really nice pay raise. Surprising for fast food. My problem is that she wanted to be his assistant for about 4 months now. She had the same opportunity but he decided against it because she is ALWAYS late or doing no call no shows and or calling in constantly. Anyways he tells everyone on the 28th of this month and I’m worried she’s going to be really upset. I haven’t even told her he was considering me since he didn’t want me to tell anyone until it was official... I feel like I’m keeping a secret from her but I came and I worked my ass off, still am. I’ve worked days I wasn’t scheduled, stayed later, always on time and haven’t called in. Plus I have experience as a manager. I’ve ran a 7-11 store and I’ve been an assistant for multiple fast food places. I know I’ve earned it, I know I’m the person for the job but I don’t think she’s going to take that into consideration or the fact that her own actions is what caused her to not get the position... idk am I a bad friend?