While I agree with all the advice that it's both foolish to risk incarceration in a foreign country for the sake a family vacation (in quite an over-rated spot, at that) and that showing up in court in response to a summons is not considered an optional activity, you can check fairly easily on whether or not you have any active warrants in Florida.
The statewide database is accessible here, and of course, it comes with a bunch of disclaimers about the information potentially being inaccurate, out-of-date or incomplete. Orange County (the county in which Disney World resides, and presumably where you absconded form) has a couple similar resources, one through the County Sherrif's Office and through the Orange County Clerk of Courts Office. The same disclaimers apply to those sites as well, though you should be able to check on the disposition of your criminal case through the Clerk of Courts site. It's not unheard of for old, unresolved cases for minor offenses to be dismissed or dropped completely after a period of time. It's not likely, but it could happen.
Of particular interest to you ought to be the following phrase from the Sheriff's Office link - Orange County outstanding warrants do not lose their validity. They still allow any law enforcement agent to arrest a person at any given moment.
From experience, I can tell you two things with almost 100% certainty.
A "bench warrant" (a warrant issued by a judge) was issued for you when you failed to appear in court. It gives any Florida law enforcement officer the right and obligation to arrest you.
That warrant does not expire. There is no "statute of limitations" because you were already arrested and charged with a crime. That warrant will remain valid until the day you die, are arrested under it, or dispose of it through the court system.
So, if you return to Florida without first disposing of the warrant and case through the courts, you'll be subject to arrest and imprisonment for the crime you were charged with and absconded on, in addition to a charge for failing to appear in court. Period.
You do have a number of factors in your favor as far as mitigating the risk of this actually happening, however. Your name has changed, and the warrant was issued under your maiden name, so a casual check won't pull up the warrant. The crime is minor (a misdemeanor, based on what you've said), so it's highly improbably to have made it into the federal system. And it's an older offense, so the warrant will be inactive by now (not actively circulated or actively pursued). All that means that the chances of you being denied entry or arrested upon entry to the US are practically nonexistent, and there's about no chance of there being anyone in Florida actively looking to serve the warrant on you.
Of course, old, inactive warrants are still valid, and still in the system, so if anything happens that causes a law enforcement agent to take a deeper look at you, it would not be difficult at all for them to pull up your warrant. The warrant undoubtedly contains your basic description and biographical details, and fact that you took your husband's last name, with whom you're travelling, no less, won't fool anyone who's actually looking. That means that if you get pulled over for a traffic violation, get injured and end up in the hospital, or even just happen to rub some bored cop the wrong way, there's a substantial risk that the warrant will be discovered and executed. For that matter, police departments routinely revisit old warrants and crimes on a regular basis (political pressure, poor crime-solve numbers for the month, etc.), so it's not like this is something that will just go away if you ignore it long enough.
If you want to risk arrest and imprisonment for the sake of a family vacation, that's on you. It's not a particularly large risk, but it's a real one. The more prudent approach would be to avoid Florida in particular, and the US in general, until after you dispose of the warrant. I'd advise that you contact the Orange County Clerk of Courts about the case and inquire about the possibility of disposing of the case and the warrant in absentia, which you'd do by paying fines and court costs, at a minimum. They may be willing to dismiss the case entirely in exchange for payment of some fines, they may require you to plead guilty or "no contest". If the latter, get legal advice on the consequences of a criminal conviction, even a misdemeanor one, on future entry to the US and your life in the UK - it's likely to have an impact on both.
The US is a huge place, with a lot of incredible, world-class destinations, not to mention the Caribbean, or everywhere else in the world that isn't Florida. Sounds like a lot of effort for Florida to me, but to each, her own.
