Some of the age-of-consent laws in this country seem a little less than rational. I think prosecutors in many places just try to use a little discretion to avoid the worst craziness.
Looking up my own state, New York, in Wikipedia
shows it to be a lot weirder than I thought it would be. It appears, from the way the law reads, that kids below the age of 16 can have all the sex they want with anyone else who's under the age of 16, and anyone 17 or older can have sex with anyone who's 17 or over. Sixteen-year-olds, however, are either criminals, victims, or both if they have any sex with anyone, including touching through clothing. Including with their steady sexually-active girlfriend/boyfriend of the day before their own 16th birthday.
I'm all for protecting kids from predatory adults, but it's a little less than sane to make sex offenders out of ordinary teens being ordinary teens.
What the older girl in Florida would be guilty of in New York, though, because of their age difference, is just a class-B misdemeanor.