You guys, am I just a paranoid ninny?

I see all kinds of potential dangers for children that others don’t seem to see. For example, we were at a family reunion over the weekend at a large park. We camped there Friday to Wednesday.
My stepdaughter attended, along with two of her kids and two of her grandkids. One of the grandkids is only 18 months old. They stayed in our camper with us on Friday night.
Well, at one point on Friday night, the camper door was wide open and I suggested that my step daughter might want to close it before the baby fell out the door.
She said, “He’s not going to go out there! It’s dark! Why would he go out there?!”
Right about then he headed out the door. She caught him just before he tumbled down the steps.

The next day, after we ate, some men were throwing a football from about 60 yards apart (I asked my brother in law, a former football player, how far they were throwing.) The one guy was standing in an area in which little kids wandered in an out of. That ball was moving. I was so scared one of the little ones was going to get nailed by an out of control ball.
The only one I could do something about was my step daughter’s 18 month old grandson. I told her that ball was moving pretty hard and she might want to keep him out of the area until the idiots were done. She looked kind of surprised like that had never even occurred to her. (Just FYI, they could have moved clear to the other end of the park and not been in anyone’s way, but I guess they just didn’t think of that.)
Later on a teenager and her dad were tossing a full bottle of bottled water back and forth, like a yard dart, which was cool, but still, would have conked a kid pretty hard had one of them hit one.

Even my own son, and his wife, drive me insane sometimes. A few weeks ago we went camping at a fishing lake. We had our own pier. Their 3 year old, who can NOT swim, was running all over the pier, unchecked, almost unsupervised. At one point I asked my son how deep he thought the water was off the end of the pier, and he nonchalantly said, “Oh, probably 20 feet.” It was like they just couldn’t imagine him falling in. Or, maybe if he DID fall in they were certain of their ability to get to him before he disappeared under the dark, dirty water (which is why I only teach kids how to swim in pools, not in lakes.)
I was just having waking nightmares of looking around and he is suddenly just not there. Drowning occurs silently.
At one point they wanted to go for a walk, asked if I’d watch the kids. I said, “Sure, but if Coops is my responsibility I need him in a life jacket.”
They opted to take him on their walk instead.

So, am I just a silly girl or are my concerns valid?