AITAH for assuming a kid might speak Spanish?

For context, I’m 30f and have spoken Spanish since I was a kid. I’m fully fluent, but I’m a non-hispanic white woman.

I was at the neighborhood pool with some family members today, and I was the adult in the water with my niece and nephew, both preteens. There was a family in some chairs by the edge of the water where we were the whole time, about an hour. They were exclusively speaking Spanish. Their kids were playing In the pool near us, and they were conversing back and forth with the parents in Spanish every now and then, but were speaking English to each other. There was a younger kid in the group, maybe four or five, and he had on a life jacket and floaties and kept tilting forward every now and then and looking kind of panicked, getting water in his mouth. This happened a couple of times, and he yelled, “help me!” (in English). I kept an eye on him and he recovered. It happened again a bit later, and he had a harder time recovering. I heard one of the adults call out to an older girl to help him (in Spanish), although they weren’t too concerned so I figured this was a thing they were monitoring, but I also swam towards him to keep an eye out because I was the nearest adult. I got closer to him and asked, ”Are you okay?” And he was catching his breath and I asked one more time but in both languages, “Are you okay? Estás bien?” and the older girl near him looked at me and only said, ”He speaks English” and kinda picked him up and that was the end of the interaction.

That left me feeling like maybe I overstepped or I shouldn’t have assumed anything? My initial reaction was hey, he‘s probably fine but I’m the nearest adult and I speak either language, so I’ll see what sticks. But I’m interested in hearing what people think, especially if you or your family speak a different language from most people where you live and others have made assumptions. AITAH?