Resently diagnosed 20 year old daughter with confusing sound sensitivity

It’s absolutely possible & makes perfect sense to me. I’m the same with music especially. It depends on a lot of things - but in regards to noise, for me it’s mostly about control. If I’m choosing to listen to music I can have it at the volume that’s best for me. Often blasting music can be a way of blocking out all the other noises that bother me. It also feels good in my body, and is one of the only ways I’m able to relax.

With the cinema, I go in expecting it to be loud. I can prepare myself. But unexpected noise, especially when it’s an odd pitch like even sometimes an irritating low whispering, or noise that I can’t do anything about can be unbearable. For example, I can always hear the sound of my fridge whining even though it’s very quiet, but it drives me up the wall!! 
It may be that since she’s started learning about autism, she’s become more aware of her own traits and what bothers her, and is starting to accommodate her own needs (like muffling noise).

From personal experience, I’d say please do take her word for it. She has no reason to say those things bother her other than they do. It can seem odd to those who don’t experience it, I get that. But she’s definitely not picking & choosing what bothers her. It depends on so many different variables. Every autistic person is very different. As the saying goes ‘if you’ve met one autistic person, you’ve met one autistic person.’ My mother didn’t believe or try to understand the way I acted growing up, and our relationship is much worse off for it. I have some recommendations of books about autism if you’d like to try reading them? I’d definitely recommend learning as much as you can & getting as many different perspectives from autistic folks as possible! 

Ask her what you can do to help, be mindful of her surroundings. Look out for things like bright lighting, a lot of people talking at once, very strong smells etc. They can be very difficult to deal with. (Although it’s not always these things, it can be anything even something that seems very small). To me those things can feel physically painful, and cause me to be really distressed/angry. If I’m in a crowded place for example, and I’m carrying too much, there’s too many people around me, I start to feel too hot & I can feel a tag sticking into my neck, it can easily cause me to meltdown.
If she seems to be struggling, ask if there’s anything she needs to be more comfortable. Just checking in with her and making her feel heard. Let her take her time, and any support you can give her to help her figure herself out, what her triggers may be and how best to deal with them, can make a big difference. 

As for twitching her hands, it could be a lot of things but it might be that she’s stimming. Stimming is self stimulatory behaviour; we all do it, things like shaking your leg, biting your pen or nails etc. But autistic people can stim differently, such as flapping our hands & jumping up and down, wringing or moving our hands/fingers a lot, even singing and dancing in certain ways can be a stim. It’s just a different way that we express ourselves, release energy, self soothe or regulate our emotions. It’s perfectly normal though :-) 

(apologies for such a long comment, I hope this helps somewhat) 

It’s absolutely possible & makes perfect sense to me. I’m the same with music especially. It depends on a lot of things - but in regards to noise, for me it’s mostly about control. If I’m choosing to listen to music I can have it at the volume that’s best for me. Often blasting music can be a way of blocking out all the other noises that bother me. It also feels good in my body, and is one of the only ways I’m able to relax.

With the cinema, I go in expecting it to be loud. I can prepare myself. But unexpected noise, especially when it’s an odd pitch like even sometimes an irritating low whispering, or noise that I can’t do anything about can be unbearable. For example, I can always hear the sound of my fridge whining even though it’s very quiet, but it drives me up the wall!! 
It may be that since she’s started learning about autism, she’s become more aware of her own traits and what bothers her, and is starting to accommodate her own needs (like muffling noise).

From personal experience, I’d say please do take her word for it. She has no reason to say those things bother her other than they do. It can seem odd to those who don’t experience it, I get that. But she’s definitely not picking & choosing what bothers her. It depends on so many different variables. Every autistic person is very different. As the saying goes ‘if you’ve met one autistic person, you’ve met one autistic person.’ My mother didn’t believe or try to understand the way I acted growing up, and our relationship is much worse off for it. I have some recommendations of books about autism if you’d like to try reading them? I’d definitely recommend learning as much as you can & getting as many different perspectives from autistic folks as possible! 

Ask her what you can do to help, be mindful of her surroundings. Look out for things like bright lighting, a lot of people talking at once, very strong smells etc. They can be very difficult to deal with. (Although it’s not always these things, it can be anything even something that seems very small). To me those things can feel physically painful, and cause me to be really distressed/angry. If I’m in a crowded place for example, and I’m carrying too much, there’s too many people around me, I start to feel too hot & I can feel a tag sticking into my neck, it can easily cause me to meltdown.
If she seems to be struggling, ask if there’s anything she needs to be more comfortable. Just checking in with her and making her feel heard. Let her take her time, and any support you can give her to help her figure herself out, what her triggers may be and how best to deal with them, can make a big difference. 

As for twitching her hands, it could be a lot of things but it might be that she’s stimming. Stimming is self stimulatory behaviour; we all do it, things like shaking your leg, biting your pen or nails etc. But autistic people can stim differently, such as flapping our hands & jumping up and down, wringing or moving our hands/fingers a lot, even singing and dancing in certain ways can be a stim. It’s just a different way that we express ourselves, release energy, self soothe or regulate our emotions. It’s perfectly normal though :-) 

(apologies for such a long comment, I hope this helps somewhat)