I have never used them, but would. I know lots of people who have used Fairy Godmothers and loved (understatement) them, including my sister. With the 7 year old, I wouldn't worry too much about leaving the little ones with a stranger. Anyhow, here is info (from UG).
Kid's Nite Out, 407-827-5444, kidsniteout.com, male or female sitters, min. 4 hours, 1 child $14, 2 children $16, 3 children, $19, 4 children $21, transportation fee $8 starting after 9 pm +$2, payment by cc, gratuity in cash, must cancel prior to 24 hours. They are a Kinder-care company
All about kids, 407-812-9300, all-about-kids.com, male and female sitters, 4 hour min, 1 child $11, 2 children $12, 3 children $13, 4 children $14, transportation fee $8 starting after 9 pm +$2, credit card needed for reservation, must cancel prior to 3 hours
Fairy Godmothers, (407) 969-9847 and toll free 877-611-4314, mothers & grandmothers, 4 hour min, 1 child $12, 2 children $12, 3 children $12, 4 children $14, transportation fee $12 staring after 10 pm +$2, cash or travelers check for payment, gratuity in cash, must cancel prior to 3 hours
Sitters from all 3 are 18+, insured, bonded, & trained in CPR. Some sitters have advanced medical/first-aid training and/or education credentials. All sitters are screened, reference-checked & policed checked. Many sitters arrive loaded with reading books, coloring books, & games. Additionally, each offers bilingual sitters.