First check about finances and what happens if you drop below a certain amount of hours as others have said.
Then:
How does your kid feel? Go with that. It seems awfully early in the game to be dropping classes. 3 weeks is nothing unless it’s the quarter system.
I’m glad my parents never looked at my grades until the final bell rang. I dug myself out of a ton of holes along the way but I’m not sure how things work today. You need to have an inkling of how the class works (curves, class assignment weights etc)
Like someone said you don’t know what a curve will look like until the end. Eons ago I made a 56 on a midterm exam and it was a C. I made a 56 on the final too-- one of the highest grades in the class–an A. It worked out.
If your kid can stay full time (or it won’t hurt financially or trying to stay on a specific track) then I’d consider dropping one course just for breathing room while getting used to the college course load.