Let me tell you that you were very lucky. My SIL came from California and managed to keep her luggage with her up until the last 8 hours of her trip by transferring it herself. It was late and she was exhausted so she let a baggage handler do it for her and he put it on another bus that was suppose to get there BEFORE her. Her suitcase arrived the NEXT afternoon. When I was in college I traveled Greyhound most of the time and not once was my bag lost or delayed. I didn't go to Orlando on the bus but I've gone up and down the east coast from VA to Conn. ,VA to Philly, VA to Ohio, etc... by way of the bus.
First, always have each ticketed person in the party bring the maximum amount of carry-ons. That way you know for sure they will get there with you. Adults are allowed 2 and a ticketed child is allowed 1. Traveling with a young child and having to transfer 5 carry ons is a handful. But with 2 adults and the fact that most stations aren't very big so you won't have too go far, it's a whole lot easier than buying new clothes ,etc..in Orlando.
Second, if you read the envelope that comes with your ticket and signs posted in the station it states that the customer is to transfer their own CHECKED luggage. The sales agent is suppose to tell you that when you check your luggage with them, BEFORE they put it under the bus. Now, many of the stations will transfer your bags for you. You don't know how many times I have heard "Oh, you go ahead and get on that bus right there and we'll bring your bags right over". I never fell for that crap! I usually had my books in there and couldn't afford anything to happen to them. Or you may hear, "well you have a 2 hour layover, we'll transfer them for you so you won't have to drag it around". Well in two hours someone CAN go through your luggage, it CAN accidently be put on the wrong bus or stay right on that one and miss the transfer. If you transfer your own like the company suggests than your bags will make it there with you.
I use to make excuses to the buggage handlers that were "just trying to be nice". Can you believe I was so soft spoken, that I was actually making up excuses to transfer my OWN bags when the company requires you do it anyway????
Or at transfer points you can follow Sheryl's suggestion. Just make sure your luggage is marked in some way that you know it's being put on the cart. I had some cheap blue and burgundy luggage in college that quite a few other people had also. And I can't believe all the black luggage out there!!!! Just have neon pink or green ribbon tyed to the handle or unique stickers on your luggage so you can easily identify your luggage from the rest.
Good luck to you and enjoy your trip.