My niece 💞

So about a year ago, my niece got placed in our home. She’s 8. Her parents (my brother and his girlfriend) were proved to be unfit parents. And if I didn’t take her, she would go into the system. Anyways, fast forward to now and we are officially adopting her in 2020. I’m genuinely so happy❤️ I love her as if she were my own. However, I don’t know whether or not I should start addressing her as my daughter. All my close friends know she’s my niece and when I introduce her to new people I say “this is my niece, Quinn”. So should I start saying “this is my daughter?”. Should I ask her for her opinion? I want her to know I love her as my own but I’ve always addressed her as my niece, ya know?