Why I always fail objective 1a Saturday morning said not home afternoon
!!!SPOILERS!!!
Pretty clear you're asking about Charlotte's objective here; if have completed all of her work events and she's at 5/5, you should get a message from her on Saturday morning asking you if you'll be home. You have to respond to this message positively in order for her to bother coming over. Once you do, just advance to Afternoon and she should show up.
If you've done all this and it still doesn't trigger the scene, follow up. It's possible there's a bug but I would have to crack open the July release or whichever version you're on to confirm that.