That's what I do, leave work, pick her up, drop her off then go back to work. Next year will be a nightmare as we'll have one in reception and one in nursery, so it will be drop them both off at 8.50, go to work, pick him up at 11.30 and drop him to private nursery, go back to work, pick her up at 3.30, do something with her (T.B.D.) go back to work, pick him up at 5.30.
You may have already done this but, I'd arrange a meeting with the nursery to try and resolve it.