Have you tried advertising for drop in care for stay at home moms or filling in for other providers vacation time. You could try to contact other providers in the area and get them to refer clients to you that they don't have space for.

I find as soon as I post on kijiji and this site I get immediate responses. But that may just be my area.

I keep a good slush fund every week so if I have a dry spell like this I can take a few slow weeks until it picks up again and still be ok financially.

Summer is tough, it will pick up in September.