You may have seen news stories in the last day or two about a 21 year old girl suing her parents in New Jersey to force them to pay for her college education. A trial judge has ordered the parents to pay $16,000 of her 25,000 tuition bill. You can read a news story here: http://abc7chicago.com/education/young-nj-woman-sues-estranged-parents-for-college-tuition/394149/
In Florida, parents are required to support their children until they reach age 18, or possibly until age 19 if they haven’t graduated from high school yet and will graduate before age 19. But parents are not required to pay for children’s college education. The law is different in New Jersey, it appears from these news stories. So, assuming you haven’t signed a written contract with your children or with your ex-spouse as part of a divorce agreement, then you don’t have to worry about your kids suing you to pay for college.
Help them learn to take responsibility by getting a job in high school; help them with financial aid applications, and so on. And help them with their actual college expenses if you can and if it is the right thing to do. But you don’t have to worry about being sued if you don’t.