My mom is freaking us out! What do we do?

She may just be getting confused with how to use her computer and taking it out on the mouse.
And just because you "read" about dementia and you "think" that she matches up to moderate dementia like you said in your post below doesn't mean that in fact your mom has dementia.
Having a stroke and having dementia are 2 different things. If you truly are worried about your mom having dementia, it's time to take her to see a neurologist and let them do the necessary tests to see if she does.
Until then, like a lot of us told you in a previous post, you and your brother really need to move out and get lives of your own.
Your mom if she requires 24/7(which I don't believe she does from what you described in your previous post)care should be placed in the appropriate facility, so you and your brother can get on with your lives.

Is she playing an online multiplayer game? Mice are usually the first target when you get frustrated playing them.

As to your questions on your profile... get a job and move out.

Your profile says Mother had a stroke in 2020.

Stoke is a brain injury. Effects & recoveries vary tremedously. Fatigue is very common. Frustration tolerance may be effected, especially when extra tired. Being frustrated by a computer is pretty normal imho!

Have you had much information regarding caring for a 'stroke survivor'?

I understand that cultures & families differ.. many live multi-generation until marriage.

Is this why you are living with your Mother?

Why do you think your Mother is so protective of your clothing choices?

How long to you plan to live together? Do you work? Study? Do you have plans to live independently?

You have on ur Profile that Dementia is involved. I would say, that she may remember how to turn it on, maybe even get on-line but once she gets there forgets how to surf the web. Or, the pages aren't loading fast enough, or she can't get where see wants to be. Anything actually can set her off and she blames the mouse.

Her brain no longer can give the correct signals she needs. Her processing and comprehension are limited. Dementia can effect her eyes. If this keeps up, I would take the computer away, its only causing her anxiety. Tell her you noticed she was having problens and you took it to have it looked at. When she asks when ru picking it up, tell her its not fixed yet. Maybe she'll forget about it eventually.

Try asking her what's going on. See if she gives a reasonable response or if she's off her rocker. Go forward with your responses depending on your analysis
Or you could remove the computer and mouse.

Computers are certainly frustrating at times! Have you had her evaluated for dementia? If you haven't and are making an appt to do so, keep notes of all the weird things she does to give the doc an idea of what's going on.

What do you do to frustrate her? Or is the computer frustrating her? I feel like throwing mine out the window sometimes. That doesn't mean I have dementia.

I was reading and she matches up with moderate dementia