"If I don't hear from you, I'll plan on picking him up".
My W does this to me. Asking me about stuff that has already been established as a precedence.
Unfortunately, I don't have any different response than what you did, which is a single word answer if able.
So at this point, I am asserting the exact schedule as outlined in the SA. There are online, shared calendars that you might utilize to further prevent these times of momentary confusion she might be having.
