She sounds very much like me. I do all those things that your DD does. I'm late 50s and have been diagnosed with autism and ADHD in the last 3 years.
It's never too late to get a diagnosis. I would strongly urge you to get the process started.
Calling an autism or ADHD diagnosis a 'label' always sounds very dismissive to me. They are both very significant diagnoses. The good thing about getting an ADHD diagnosis is that there is medication that is very effective and has been around for decades (so very tried and tested). And really it is like any other diagnosis that comes with very effective treatment, getting a diagnosis and treatment is a no brainier.
Since going on ADHD meds, my anxiety is now at reasonable levels, I am far more able to get boring things done too. To be honest, the anxiety improvement is so great, it would be worth taking the meds just for this.
The meds have also stopped my impulsive eating. A lot of us ADHDers have problems with out weight because we are constantly seeking out dopamine and gorging on carbs and sugar can feel like it helps. Last week, I decided not to have any meds for a few days . 3 days in, I decide to have a slice of my mum's delicious Homemade Christmas cake, then I had another slice; then I looked at the remainder and thought I may as well tidy it away into my tummy. About half an hour later, I was absolutely shocked at myself - I'd probably just eaten 1500 calories in cake. I decided the no med experiment was ending immediately.
In addition to ADHD and autism, I also have a chronic illness (ME/CFS) which has made me too ill to work. My psychiatrist has many patients who also have this illness and she is comvinced that it is linked to neurodivergence and has also told me that the stress of living with untreated ADHD would have been a factor in me getting ill. So having a diagnosis and treatment is protective of your physical healh. Plus it is known that autism and ADHD are linked to many other signifiant health problems plus also many other types of problems such as gsmbling, crime, drug addiction, poor educatiobal outcomes, over spending and unstable careers. Oh and domestic abuse (which happened to me).
OP, I hope this long list of possible negative outcomes has convinced you to get a diagnosis or diagnoses for your DD. The disadvantage of not having a diagnosis far outweigh any disadvantage of having a diagnosis (and to be honest I have yet to come across a single disadvantage of having these diagnoses.
I have recently started having autistic shutdowns. They are trigerrd by stressful events and a bit like meltdowns except they are quiet and can last for days. When I am shutdown, I can't talk to anyone, can't eat, can't read, can't cook or do anything much apart from lie on my bed, listen to music and wait for it to pass. I had a shut down a few days ago because my GP sent me a message, telling me to book an appointment via a link except there was some kind of technical error and i couldn't book. I phoned the surgey and the receptionist said she couldn't help! Later that same day, I had an appointment witb the surgeey's pharmacist. Sbe said she would ask a colleague to sort it out and call me. Tbey didn't. After that, my shut down started and i was unable to engage with the surgery. By the time I was better, the link had expired: I had an appointment with my psychiatrist that day and told her what had happened. I also told her about my query to the GP. She said I needed an urgent appointment because it is potentially a serious problem and the GP's system did not meet my needs. She wrote to the GP that evening saying I needed an urgent appointment and explaining that the process of trying to get an appointment had caused a shutdown.
People often ask me why I bothered to get diagnoses so late in life because, they say, I have managed up until recently, The point they are missing is that I have spent something like 55 years working 10x harder than everyone else to make it look like iI was managing but I wasn't. I've got a degree but my A-Levels went tits up so I ended up doing a rather unsuitable course. I then started my career and despite working hard and being liked etc, I never once got promoted. So yes on the surface I coped by paddling like crazy and still did not fulfill my potential.