My best friend “took” my future daughters name..

So when my best friend was 36 weeks pregnant she still didn’t have a name for her baby girl. So she asked me to throw out some names for her. So I send her a million names and the name I fell in love with and knew I wanted to name my daughter that was Mackenzie. When I sent her all these names she didn’t even respond to mackenzie kinda skipped over it. Then when I went to visit her in the hospital I asked What name she picked and it was that. So my question is can I still name my daughter Mackenzie or is that a no no. We’ve been friends for 12 years. I see her maybe once or twice a month but I sometimes watch her daughter. And my other question is let’s say I do name my daughter Mackenzie. Are there other ways to spell it? Help me.

Note: my best friend gets mad and holds grudges at literally everything. I even asked her if she would be okay with it and she was like “how can you name your daughter my daughters name?” Soooo yeah.