Except she said it first, and versions of it have appeared since she said it, but not before she said it.
Telling me that it's just a sentence isn't persuasive in any way. Showing me something mostly similar from before 1986 would do a lot more to persuade me.
Nor is telling me "it's attributed to Grace Hopper." It's a special kind of hell to google something for 20 minutes, return, and have someone throw you a Wikipedia link.
Oh, you don't know who the Beechers are. They're from the 1800s.
Some places say Henry Ward Beecher (brother of Harriet Beecher Stowe). If I had to guess, though, it's hundreds or thousands of years old.