Go around your neighborhood and ask if you can mow lawns. This is what I did when I was your age and it definitely brings in a profit. Another fun thing I did was organize a weekly "kids camp" where you go on one or two hour long educational adventures with young kids and have each kid pay $10 for each time. You will make a ton of money doing this if you organize if well enough.
Babysitting
Bake sales
Crafts
Sell garden produce at the farmer's market or roadside stand
Walk people's pets
Organise a car wash. Bake cookies. Sell lemonade. Pick strawberries in the fields, make them into jam, and sell it. Become a woman of the night. Babysit.
forget the lawn mowing - you are a girl and you wouldn't want to do that + there are too many landscape companies that take care of folks lawns now.........what you can do is ask neighbors, especially the older folks, if they have small chores you can help them with - cleaning windows, reorganizing / cleaning a garage, weeding, etc - think about it and you will come up with ideas ;]
cleaning jobs, dog walking, car cleaning, leaflet distrubiton, saturday jobs in hairdressers, or look on job sites :)
run an ad - help - my brother is innocent and I need ___ to prove his innocence
