Can you tell her ahead of time that you are handling it? Maybe not permanently taking it over, but as in, ill do this chore - check the kids clothes or lunch or whatever - for you this time, you can just drink your coffee. People with control issues dont play well on teams. What you and a good friend might do interchangeably for each other without much thought, becomes a big deal with someone who is marking her territory. Thats been my experience.