I am in Canada, so we don't have "Early Intervention" per se. Nor are there scheduled pre-school screenings. I'm not even sure if there are screenings in elementary school anymore as I don't yet have a school-aged child, and we don't have school nurses or anything like that.
I do run a licensed home daycare, and I am pretty certain that if I were to phone our community support office they would be able to schedule an evaluator to come to my home - but of course the parent would need to give consent for this to happen. One of the other providers in my agency went through this process with one of her kiddos, and the child was diagnosed with ODD.
I want to make it clear that I am NOT trying to diagnose this kid myself. But it is pretty clear that she is definitely a quirky kid, and something is going on. Whether she just needs some behavoural support, or if there it is something else is not my place to decide, nor am I attempting to do so. I do have some training in typical child development as I am a licensed provider, but I am in no way qualified to diagnose. I am exposed to a large number of toddlers and preschoolers in my own home, other kids in my agency (we have a play group once a week), my friends' kids, and from volunteering in our church nursery and preschool room. And this child stands out.
I do feel a lot of responsibility about this. I have this child from 7:30 to 4:30 five days a week. If it turns out that there is an issue and things could be improved by early therapy or treatment.... but I am the only one who notices an issue, and I never say anything.... I would feel quite bad about that. I would feel like I failed the child because I never spoke up on their behalf.
So I did bring it up, and I feel like I have fulfilled my immediate responsibility. The parents will need to take it from here. If, in a few months, things don't improve and the parents still haven't taken any initiative I will bring it up again. But I don't want to alienate the parents in the process and have them switch daycares.
A pp suggested that perhaps this is being followed by the child's doctor. I am confident that this is not the case. I have her all day, every day (even when her parents have days off, they still bring her to me). I would know if they were taking her to appointments, and they are just not.