You're going to have to separate them soon. If Norberta gets all the basking time, then Mufasa won't eat. So as soon as possible, They're always happier on their own. You need a
UVB light, basking isn't enough. UVB is sunlight for them and necessary for them. So you should be getting an 18" Reptisun 10.0 and putting it inside the tank (check DIY section to ask how you do this.)
Read the care sheet to the right as well as the lighting article to get the right info, but they have to have UVB it's essential for growing strong bones and digesting properly.
How are you feeding them, together in the tank? It would be good for you to get some sort of feeding bin to feed them separately, so they both get alot of bugs. Their bugs should be dusted with calcium 5 meals a week, then vitamin/mineral powder for 2 meals a week, That's also essential, as they won't get calcium from their bugs or greens (which they probably aren't eating yet) and they won't get all the vit/min they need from their food either.
They also need baths every 2nd day for sure but for babies I suggest daily, 20 min warm baths. They can have their baths together as long as you supervise.h
It's really important that you get them into their own tanks, so they have their own space. I have 5 dragons, 1 yr old Castiel, 1 1/2 yr old Cierra & Nathaniel (brother and sister), Gabriel 4 1/2 and Leo 8 yrs old. They each have their own 40 gallon tank with basking/UVB lighting. They all get baths every 2nd or 3rd day and still get calcium and vit/min (I use liquids). They all get dubia roaches, or super worms or both, plus collard greens and squash.
You can get an Accurite temp guage with probe at any Walmart or such in the garden section, doesn't cost much & it will give a proper temp on the basking spot after 45 min.
Let me know how it goes with getting all this organized. Once it is, you just have to get a new UVB tube every 6 mo, the rest will be done! That's the only hard part is getting everything organized at the beginning.
Keep me posted, k?