Does this make sense or am I being precious?

My son was sleeping but woke up in a panic because I was no longer in the room.
Shortly after I returned and cuddled him he drifted off to sleep. He currently doesn't seem to like his cot. He just wants to be as close to me as possible all the time.
So in the day I try and create distance by doing chores and leaving him to get on with playing with his toys. (In view)

When it comes to night time I try to remain calm and quiet. Any noises come from the sound machine and I avoid talking to him. This is so he understands that this is time for resting.
My mum is so desperate to have time with my son that she has gone as far as taking him out of my hands because he was crying.

Then asking me if I think he needs feeding or changing.
So I told her get on with it since you decided to just take over.

She's in there blowing on his stomach and he's crying more and louder because he doesn't like that which I've told her before.
I'm fuming right now.

I told her last week in the week I only need help with the dog. If she wants to spend time with him she can have him on the weekend, to help me out.
But this has just completely undermined me..