Don’t feel guilty. You’ve tried and given it your best shot.
If there is no consistency with home and daycare, you will be fighting an uphill battle.
I would just word it as not being able to meet the child’s developmental needs.
Don’t get into the specifics.
Outline the last day of care and be specific about what money is outstanding.
Not every family is a good fit for the group.
Cut yourself some slack, and know that you’ve done what you can.