Am I wrong for being annoyed?

I have a 7 month old who eats baby finger foods. My mom always tells me that he's choking, so I go up to him and he's only doing that coughing thing (NOT choking). 
Then she gets mad because she thinks I'm going to let him choke on his food. 
I know when he isn't choking. I've done my research on baby reflexes. 
She always intervenes and it pisses me off. 
It's my child. Not hers.