I do not believe the original Star Wars movie was made for kids. It’s been stated multiple places it was an “escapism movie.” Just because it’s a fun story does not mean it had to be targeted at children. It was one of those rare movies no one wants to make anymore which was made “for everyone.” Sure there was a lot for kids to like in Star Wars, but the story and characters were interesting enough for it to appeal to adults. (Scenes like Uncle Owen and Aunt Beru’s corpses burning up would not be in a movie made for kids. Also see: Truth serum droid, violent shootings which were censored for SE, bloody severed arm in the cantina, etc.)
This was taken even further with Empire, as the character relationships get more complex, as does the drama. Jedi follows this balance more than most people give it credit for, though the line between the kid stuff and adult stuff is much more pronounced. The ewoks seem so much like kids fare, while the Emperor’s throne room sequences have heavy adult drama. (And actually when you think about it, sure they’re cute, but the ewoks kill a lot of people and even intend to roast the main characters alive. The fact that they’re cute offsets the darkness of them and adds to the bizarreness I feel.)
It was much later that George decided to say he always made the originals for kids. It really wasn’t until Jedi that kids were taken into a grand consideration.