Did I make the wrong decision???

[apples and bananas]

An alternative would be to allow it but do it on a month by month basis. You could let them know that you are willing to try to lmited days for now and see if you can manage it budget wise and if the kids can manage it (often kids on fewer days are harder to handle. Less consistency)

If it becomes too dificult to handle you will give appropriate notice.

This way you could put up the advertising and if something better comes along let them know that you just can't manage it, offer their origional agreement to them or send them on their way.

Good luck to them finding care 2 days a week. Very hard to find.