A.G.
You need to take care of this problem as soon as possible. I used to live in a neighborhood that had tons of kids, and my yard was right in the middle! Mostly, I didn't mind having all 10-20 kids playing in the backyard, but when it got too wild, or when too many of the bigger kids were hanging out with my younger ones, I would tell them to leave..bluntly!! If they wanted something to drink I would tell them to go back to their house and get something. If they wanted to go somewhere with my kids, I would tell them that this is my time with my kids and they couldn't go. You need to set your rules and discuss them with your daughter, make her understand that SHE is your only responsibility and not the other kids, that you have a budget and cannot afford to take her friends everywhere and so on.
The other kids are taking advantage of you and your house, etc. and so are the other parents. You need to introduce yourself to the parents and explain your new guidelines. Since the parents work, suggest that your daughter goes over there on the weekend. If that doesn't work, and the kids still want to play, make it outside only. I hope this helps, I was known as the meanest mom on the block with the most rules, but they still kept coming back.