New bearded with possible issues

I got a bearded from a breeder a few days ago. They said she was born June 15, which make her 3 months old, but she is barely 6 inches long. She was in a small tank with one of her siblings and no uvb light. The breeder said I didn't need one but I know I do. Right now I have a zoo med compact bulb and a red heat spot light that is 75 watts. I do have a brand new 100 watt, should I use that instead? I am going to order the long reptisun bulb today, but should I get 24 inch or look for 36 inch as that is how long the cage is? I have only gotten her to eat a few crickets and no veggies. I am worried and want to do my absolute best for her. Any advice will be much appreciated. I have been taking her out in the sun as much as possible (I am in Florida) to help her get her uvb until I get the reptisun. Will her growth catch up? What can I do for her?

Thats misinformation from the breeder, unfortunately. They definitely do need a UVB light and it's worth investing in a good one to ensure they have access to bright sunlight levels of UVB. Since you're trying to imitate natural sunlight, I recommend using a bright white basking light rather than a red one. I've had good luck using outdoor PAR38 halogen flood lights from the hardware store. You want to use a wattage and set it at a height so you hit a specific range of temps. Shoot for a surface temp of about 100-105 in the basking area and about 75-80 on the cool side. That will give a nice gradient with plenty of options to choose.

The UVB light is similar. You want some areas with intense UVB and other areas that are "shade" with little to no UVB so she can choose what she wants. The size and type of bulb you use depends on the size of your enclosure. What are you using? What are the dimensions? How high above the basking area do you plan on setting the UVB light? It's great that you are able to bring her out in the Florida sunshine. That should be a big help so I'd bring her out as much as you can.