Leave out the "since you had no intentions of doing a half day for E" part, and leave out the question. Just say, "I plan to be there to pick up E at 4pm as usual tomorrow. Let me know if you have any questions; otherwise I'll see you then."
Since she's not responding to you, don't leave the ball in her court with a question - you will likely not get what you want or end up with an unclear agreement. Say how it will be and leave it up to her if she wants to challenge it somehow. You're putting words in her mouth with the "no intentions" part and it won't win you any points.
Adinva 51, S20, S18 M24 total 6/15/11-12/1/12 From IDLY to H moving out 9/15/15-3/7/17 From negotiating SA to final D at age 50 5/8/17-now: New relationship with an old friend __ Happiness is a warm puppy.