I would not be so quick to shut them down. It is a mistake to think that she cannot be assessed at 3 years old. My youngest daughter was assessed at 4, and she did not show many of the characteristic traits that people think are "typical" of autism.
One trait my daughter is very well known for is her absolute charm. When the doctor assessed her, she said "this is easily the most charming child I have met in 17 years of practice." Then she looked at me sideways and said "you know that's not normal, right?"
She was tested, then the test results were sent to a second specialist, then she was tested again with an occupational therapist.
The results were conclusive. She is autistic, even though she dazzles people with her wit and brilliance, and socializes like there's no tomorrow.
As long as she is in a tightly controlled environment, she glitters and shines like she's on the red carpet at the oscars. However, put her in a normal situation and after about a half an hour, the people she's talking to start to look at her sideways and then make excuses to leave. They know something's wrong, but they cannot figure it out. It's because she cannot maintain the train of the conversation. Her responses begin to diverge more and more widely. Eventually, she will be exhausted and she'll go climb under a table or behind a clothing rack, or lock herself in the bathroom.
The idea that there is a defining set of characteristics is wrong, wrong, wrong! Like the saying goes, if you meet somebody with cystic fibrosis, then you know about cystic fibrosis. If you meet an autistic person, then you've met an autistic person.
If there is at all a history of autism in your family, or if the father was over 40, then really do keep at least half an eye on her. This really is one condition you want to get a hold of as fast as possible.
Max was speaking at 9 months. She had over a dozen words, including door ("dowah"), finger (doe-doe), toe (feet doe-doe, which sounded like "peep doe-doe"), buh! ("Bird" but really meant "something flying overhead"), water (badow), out, up, yes, no, mama, Dada, keekah ("kitty-cat"), and "goggie" (dog). By 13 months, she had stopped speaking and was not even saying mama anymore. The reason for this is because she realized nobody except her family could understand what she was saying and that she didn't sound proper, so she shut down out of frustration. It took eight rounds of speech therapy to get her going again.
She is brilliantly quick to pick up on physical things. For example, she watched a bunch of guys being taught how to do hockey slides while ice skating. After about 5 minutes, she did a perfect hockey slide. In karate, she saw someone do a spin kick, so she did a spin kick.
But even though she is very friendly and very charming, she has one friend. Friends never come to visit her, and she very rarely visits friends unless the parents ask her. She's been to exactly one birthday party in her life that wasn't her own or a family member's.
In school, she got 90 on her midterm marks for math, then promptly stopped doing anything at all. She failed the year.
She took 5 years of French immersion and tested out advanced enough that she was exempted from taking French high school credits. So I thought it would be a good idea to have her take french, as it should be an easy, relaxing credit for her. she did not turn in any work and failed.
It sounds like an awful thing to say, but I often wish that she was more profoundly disordered because at least then outsiders would see there's something wrong and stop telling her she's just a lazy gadabout.
But then I think of my oldest daughter, who is also autistic. I was told 35 years ago that girls don't get autism unless it is the classic headbanging variety. My poor oldest daughter was left to twist in the wind, being bounced from one wrong diagnosis to the other. She is virtually housebound now, virtually unable to navigate socially, even when it would be in the best interest of my granddaughter.
Who also shows the same signs of autism in that she's very brilliant and charming for her age.