I'm another one who instantly recognised the description of Huntington's. My dad died from this awful disease four years ago - I was his sole carer. Two of his brothers also have it. Myself and my brother are "at risk" which means we each have a 50% chance of having the disease too.
Just a couple of points - for those who say they've never seen it present as naivety and saying yes... Some of the cognitive changes which occur during Huntington's Disease include a lack of self awareness, an inability to problem-solve and also a difficulty in prioritising. If you read between the lines you can see how these cognitive difficulties could very easily lead to someone who is naive and can easily be persuaded to agree.
My dad only lost his motor functions towards the end - he was very badly affected cognitively from a relatively early point. I was heavily involved with a Huntington's Disease research panel and also the local HD group - there were others who lost far more motor function earlier but remained relatively intact cognitively until later on. Huntington's has a very unique presentation from person to person but the personality does undergo a very big change.
I've not been tested as I can't bear to know if I'm positive. I'm a coward. I also have an ASD son. The idea of not being able to care for him while still being physically present is horrendous. I don't want to put him through what I went through with my own dad. I'm now 43 and the chances it will start to show soon if I have it. It's awful living with the shadow of this disease - and I'm someone who always thought they'd face things head on.
I'm not going to have a go at anyone specifically but don't judge things you don't know enough about. It's a bloody devastating disease and the presentation OP describes is entirely feasible. I lived and breathed this disease for several years while caring for my dad and met many, many sufferers and also people who like me, are at risk.
OP - re the CAG count, your wife's neurologist will already have this information. It's what they look at when they diagnose the disease. However, not all doctors are willing to tell their patients what their CAG count is. The reason for this is that it's not been completely proven that CAG repeats are absolutely linked to the age of symptomatic onset. There seems to be a link in some cases, but not all. Therefore, some neurologists have been reluctant to give out CAG scores as they don't want to cause either false hope (for a late onset) or a panic. This article describes it really well:
insidehd.com/the-in-between-years-part-5-1786644b0eac
Also, my dad never had a brain scan in the whole time he was under the care of the neurologist, post diagnosis. It's kind of pointless. There's drugs they can give you to slow the motor difficulties but these tend to make the cognitive problems worse. It's a catch 22. Care is generally based on reported symptoms and observed decline in neurological function.
What I would get your wife to ask her neurologist is whether she's been added to the clinical trials database - I think it's called EHDN? Something like that. Neurologists in hospitals enter their patient details and then when a trial comes up that fits your wife's criteria she can join it. It means the potential to access new and cutting edge treatments before they're widely released. Lots and lots of developments have been made in HD recently, including one big landmark discovery. Your wife is young and not yet heavily symptomatic so it's worth getting onto the trials if you can.
Re benefits - I doubt she'd qualify for anything yet. She's not functionally impaired yet, a diagnosis alone means fuck all.
Sorry to have diverged from your original subject. To have her shift doubled and then have to walk home very late in the dark is appalling. I think my focus would be on making sure that it doesn't happen again. Maybe your wife needs to have a chat with her employer and make it clear that she won't be put in the same situation again. It sounds like poor planning from management.
My inbox is always open if you ever want to chat about HD. It's a shitty hand you've both been dealt and I really feel for you.