Using TV to calm down baby

I'm just wondering if I'm overreacting a bit to this. I have the tv on during the day, but I don't have baby facing it. If he's awake I won't watch it of course and I'll interact with him, unless he's sitting obsessing over his hand or he's distracted with something else and quiet. Anyways, I had no intentions of introducing screens to him until he was a bit older, a minimum of one years old I was aiming for, but my mam always seems to use it as a way to keep him quiet.

My boy is 11 weeks old on Friday. He loves looking at lights, and we have a projector we use if we want him to be quiet for a little while, but its not something we use for sleep. He would not sleep at all if we used this at night for him, he'd just stare at them until he got bored and started to whinge. My mam keeps using the tv as a way to calm baby and keep him quiet because 'he is just looking at the lights'. I don't know why, but I dont like it and annoys me how she tries to subtly do it. For example, my son was crying and screaming bloody murder a few days ago and she kept him over her shoulder, rocking him and shushing, but so he was facing the tv and she would move to the middle of the room so he was directly looking at it. If baby wouldn't calm down, she'd adjust slightly so he could see it more. If he's doing that with me, screaming and crying, he settles down after a walk around the house, usually. I kept telling her this, too. Go for a walk around the garden or the house, he seems to find it calm in the kitchen for some reason and I can be walking in circles in there and he'll go quiet. But every time he cried, she would get up and face him towards the tv. I did take him at one point and he did start crying, and I saw the look on her face saying 'you should have kept him in front of the tv', but he was overtired and needed to sleep. He had only had a half hour nap and been awake about an hour and a half at the time, and showing him the tv won't help him sleep. Yes, he needs to calm down first, but there are other ways to do it.

I don't know if im just overreacting because she is just trying to calm him down and she isn't exactly sitting him in front of the tv and leaving him be for hours on end, but like I said, walking around the house and white noise usually calms him down, too. He'll often fall asleep quite nicely to white noise even if nothing else has been settling him. I've mentioned it a few times and the responses are always the same - he's just looking at the lights, or, it calms him down, or, he doesn't know what he's watching. I really don't know how else to bring it up if she keeps doing it or even if I should. She comes over 2 or 3 times when my husband is on the late shift, which is every other week. I feel guilty saying anything because she does come to help me so I can do the cooking and cleaning and relax while my husband is at work because he doesn't get home until after midnight on the lates. Am I just overreacting or should I put my foot down? I'm tired of mentioning it as well, frankly, to everyone, but my mam seems to be insisting on doing it every time baby makes a slight cry. She always says that we were shown the tv, but it wasn't what I wanted to do. I'm not trying to shame anyone who does do this, but I just wanted to avoid it as much as possible for the first year