I think you maybe referring to Theory of mind which means that you cannot understand the world from another person's point of view only your own. The ability to put oneself into someone else’s shoes, to imagine their thoughts and feelings. It is also known as mindblindness theory whiich proposes that children with autism and Asperger’s syndrome are delayed in the development of their Theory of Mind, leaving them with degrees of mindblindness.

https://en.wikipedia.org/wiki/Theory_of_mind

I imagine you probably thought your daughter's psychiatrist was referring to some scientific theory. But theory of mind (not "mind theory", although the confusion is understandable if you thought it was a scientific theory) refers to the ability to understand other people (mainly, though potentially animals too) as also having thoughts, intentions, feelings and so forth. Not just in a general "this is a person who thinks and feel things"-kinda way, but also specifically to infer what another person might currently be thinking or feeling. Not like mind-reading, of course - the idea isn't that you can literally know another person's thoughts. But most of us, in our daily interactions with others, are constantly trying to guess what motivates the actions of other people, what type of mental state they are in, and so forth, and this helps tremendously in order to make those interactions successful.

People with autism seem to commonly have deficits in theory of mind - that is, they have trouble figuring out another person's mental state or intentions. However, as with all neurodivergences, every person is different, and also recently some research has come out that challenges this idea. This newer research has found evidence that the apparent theory of mind deficits are reduced when people with autism interact with each other rather than with neurotypical people (and, conversely, that neurotypical individuals appear to have similar theory of mind problems when trying to understand people with autism). So, perhaps it's not that people with autism have trouble understanding the psychology of others in general, but rather that they (and people in general) find it difficult to infer the mental states of people who don't think like them. Or at least, that may be part of the explanation - there may still be genuine theory of mind deficits at play (in some individuals) as well.

Imagine I show you a box of chocolates. I ask you “what do you think is inside the box?”, and presumably you answer “chocolate”. I open the box, and show you that I’ve replaced the chocolates with marbles. Now, your friend comes inside the room, and I ask you “what does your friend think is inside the box?”

Young kids will say “marbles”, because they know there’s marbles inside. Older kids will answer “chocolates” because they understand that their friend sees a box of chocolates and has no way of knowing it’s actually filled with marbles. This is called a “theory of mind” — you have a mental model (“theory”) for how people have separate minds with separate knowledge.

One of the difficulties that come with autism is precisely around developing that theory of mind.

Your child doesn't think of you as another thinking entity. To her, you don't have your own thoughts and emotions and desires. Hers is the only mind in the universe.

When you disagree with her, this is wrong because obviously (to her) you want what she wants. Her wants are the only wants that exist.