ETA: I know you are looking for words of encouragement. I can tell you that I KNOW you can do this. You will find a way. Check with the YMCA, your county (ours is called REC-PAC) and others...
Please understand that I am NOT trying to be mean. Your daughter really does deserve to have stability instead of being taken care of by different people. I am sure you will be able to find someone - even a high school or college student - who will be able to help you out.
J.:
Sorry - but your daughter deserves better than being tossed between three or four family members.
Pick a day care and get her the stability she needs. Find a great summer program - our county has a GREAT program - you can do 0830 to 3PM or 11AM to 6PM - and if you don't make enough money - there is a "scholarship" fund they can use.
Drop in care is not fair to the business owner. They count on stability too to keep their business open. Talk to them about your situation and find out who can help you with it and your schedules.
Same with the day care - if you can't afford it - apply for State Aid and get the day care help you need. If you don't qualify - due to your husband's raise - get your finances under control and find a way to make day care happen. Start with the Dave Ramsey plan so that you can control your finances instead of them controlling you.
Good luck!