<human>: Can you provide a brief rundown of the text in within 3 sentences?

My brother [39M], Parents [70s] and I all suspect that my sister's son, "Jake," is probably somewhere on the autism spectrum. Whatever the diagnosis, however, it is obvious to us that Jake's behavior is not normal. My sister acknowledges that he can be challenging but thinks his progress over the last few years is proof there's nothing wrong, and he'll grow out of it.

The rest of my family is hesitant to tell my sister and her husband how they should be raising their child, but we're also, of course, very concerned for Jake's wellbeing. My sister has the resources to provide Jake with anything he needs, but I would really appreciate any suggestions for how we (or any one of us) can broach the topic with my sister and tell her she needs to make quick and drastic changes to address her son's needs.
<bot>: My Sister' thinks her son has personality issues, and it's apparent to everyone else in the family that he has an undiagnosed disorder. We don't know how to talk to her about it.