Before you decline, talk to the mother. When dd was in K, I had her b'day party at the park across from her school after school. If a mother declined because of work, I told her that if she sent a note to school allowing me to walk her child to the party, all she had to do was pick him up when she got off work. I walked about 5 children to the party. We had hotdogs, cokes, and cake. Everyone was happy.