The diagnosis of the 3YO will provide access to several services where I live (NY state), and she's already been enrolled in an early education class with others on the spectrum. Before turning 3 she was receiving about 2 hours of in-home speech and therapy per week.
Get her to a doctor for diagnosis, as early services can be very helpful in long-term outcomes. We also had early services for the 14YO that unfortunately were not entirely effective due to the seriousness of her condition, but we're optimistic that the 3YO could be in general education classes by elementary school.
I also highly recommend living in a place with a decent school system and a well staffed special education department. Without that, my daughter would be floundering academically and socially isolated.
The right next step is to get an actual diagnosis, in my opinion. You might be off-base in your suspicions, or it may turn out that your child is more affected than you suspect.
Autistic people are routinely over-medicated, and that over medication one reason for the difference in life-span for autistic people.
In the U.S. Federal law requires public schools to provide some forms of accommodations. Search for "section 504 of the Rehabilitation Act of 1973". Accommodations range from the trivial, like getting to sit up front in class or getting reminded to write down assignments, to things like getting an extra day for homework or getting access to remedial teaching or tutoring. Some of these could greatly relieve stress.
"My kid never even realizes that homework was assigned, and the teachers are not good enough about noting assignments online in a timely manner, so she's always late to turn them in or misses them completely, so she's failing her classes even though she gets A's in all the tests!" -- if you find yourself saying something like that, then you need some 504 meetings! An official diagnosis from a psychiatrist might not even be necessary, i don't know, but certainly a therapist might prove useful anyways in helping your child get more out of life.
(If that statement sounded weird, that's the point.)
That's an interesting and problematic aspect.
My wife is a teacher and has started to encounter that attitude more frequently. "He gets angry because he is ${diagnosis}, you can't punish him for it". But when it disrupts the class, and encourages others to behave similarly, then some response is needed to mitigate the situation. There is a responsibility to the class as well as the individual.
Defining that response is the problem. In one example from a local school the child was given shorter school hours as an incentive towards controlling their behaviour. Which is exactly the opposite of what 'normals' receive, detention for disruptive behaviour.
Remember: Autists have to learn and cope with this new social situation first before they have the strength to progress intellectually. But even when the kid is normalizing, careful not to overwhelm them again, because they might use up all their energy for the school day and just break down at home.
School is a horrible place if there's the same treatment and the same expectations on every kid.
Who says this mitigation has to be a punishment? I am also skeptical concerning punishments for neurotypicals in similar situations.
We don't begrudge wheelchair bound students ramps to access rooms. We shouldn't deny children with "${diagnosis}" driven behavior alternatives to punishment when it's appropriate.
Edit: For what it's worth, I also think punishment is too often a first-resort by schools for all children. This is a complex issue driven in part by the horrific way we under-fund schools. Many of these problems would be much less significant if we funded schools well enough to provide the support they should (and are legally required to).
Having the right diagnosis is important. Who wants to end up taking powerful medicines for the wrong condition?? Sure, if you have no diagnosis then you won't take the wrong meds either, but that's not a reason to avoid a diagnosis.
That would be true no matter what. There's no basis for the full concept of "free will". Everyone is a product of biology, culture, context, etc. etc.
The question is what capacity people have to behave in various ways given certain contexts. Most people can behave "normally" given the right context to do so. I suppose your daughter does not have that capacity (at least not to the normal level). So, having realistic expectations helps a lot.
We all get angry at times, but it barely ever helps anything, and that's true regardless of all these other questions about autism etc.
We did not get a specific diagnostic, and I'm not sure it's worth seeking one. As far as I know, the diagnostic is not scientific, so I wouldn't consider it a strong validation of what we're experiencing. However, a diagnostic might make it easier to explain to our family and friends what is going on, and talk about it.
Any thoughts?