Given the option, I prefer to be perfectly on point with just the “right” levels of protectiveness and curiosity. When that’s not an option (and it frequently isn’t), I’ve decided I’d rather be slightly (emphasis on slightly) overprotective and overcurious than the alternatives. The tricky part is determining where the lines are, but there are some handy rules of thumb.
For instance, I figure that if you would ask the same question if a casual acquaintance told you their late night ended around eight in the morning that you would if a family member told you the same thing, you’re probably doing okay.