My ex wife has asked for her flat keys back even though it was part of our coparenting agreement to have access to our daughter at all times - England

Hi all, first of all this is a throwaway account for obvious reasons.

Background story: after using amicable to do our divorce, we agreed that she would keep most of the assets (about 90% of the total), but in exchange she would be financially responsible for our daughter’s expenses, which she has to a certain extent but I’ve been responsible for feeding her the 50% of the time she spends with me, as well as buying her non school clothes and shoes. I don’t mind this, as I love my daughter and do not need the money, and I still fiercely love my ex wife, the divorce was not my idea.

We also agreed that we would coparent, as with both of us working we would do our best to keep things as flexible as possible. As part of this arrangement, I would have a set of keys to her house and she would have a set of keys to mine.
Today, out of the blue as I was dropping my daughter off with her she asked for her keys back citing that it was “affecting her mental health”. Of course, I handed them over as these are her keys and her house, but it doesn’t sit well with me that this gets in the way of my ability to access my daughter.
This is on the back of her also asking me to remove my daughter as my dependent with our GP, which also didn’t sit well with me, but I let it pass in order to preserve the cordiality of our relationship.

I would prefer to keep our relationship as good as possible, but I’m worried about having access to my daughter limited, as well as limiting my ability to help in case of an emergency.

Is there anything I can do to ensure I continue to have unrestricted access to my daughter? I do not need to have the keys back, but I would like to have some sort of agreement outlining these terms.

Thank you.