Quick question

My family has a bearded dragon that I do not have main responsibility over. I just read that bearded dragons do require UVB lighting.. Is it true that they really do need it? Like, actually need it and don't just benefit from it? I think she might of had one before, but then it burnt out.

Yes, Bearded Dragons need UVB lighting and generally you want the dragon to be able to get within about 10" of the light (assuming the light is in the cage).
As far as I recall (been a while since I had my iggy and bearded) the UVB lights should be changed every 6 months. I had used reptisun 10.0

Calcium and UVB so the lizard does not develop MBD

I use powersun mercury vapor bulbs for mine, 100w, that way they get heat and uv in one go. Beardies need uv, or the can't process calcium and their bodies start eating away at their bones in order to cannibalize the calcium. This condition is known as mbd.

Just to pile on - yes, they absolutely need UVB light. If you don't use the combo light like alter-echo mentioned, you would want to make sure the rays from the basking light and rays from the UVB light overlap a little. All of this aids in their physical development, ability to process foods and absorb calcium.

UVB should be replaced every 6 months regardless of if the light goes out or not.

There is a great bearded dragon forum here: https://beardeddragonforum.com/ if you want a more in depth discussion and understanding of the husbandry requirements for beardies.

Thank you for the help! I will make sure to tell my family when I can. I also bought some calcium + D3 supplement for my future garter snake a while back, but I ended up getting a BP so maybe I'll let them have it.

Yes, UVB is an absolute MUST. I would highly reccomend the t5 ReptiSun 10.0 HO. It can be found on Amazon for around $25.