To correct the MBD, you will need to get some liquid calcium gluconate from a vet and use it until the MBD is corrected as well as provide he with proper husbandry from now on t keep it from coming back.
It's important that th temperatures are right so she can digest her food properly and even more important when she becomes sexually mature, along with a controlled diet, to keep her from laying large clutches of eggs likely becoming eggbound, and developing other issues. More about the egglaying issue later.
Basking temperature should be kept at no more than 80F. The light should be a white light....a regular white (not LED) incandescent household light bulb of a wattage that produces that temperature is usually recommended. You can test the basking light to make sure it won't burn the chameleon. Hold your hand inside the cage, palm down against the screen...if you want to move your hand it can burn the chameleon.
It's important to provide a proper UVB light.
@Beman has already covered this. More about this later too.
It's important to feed/gutload the insects properly as well as dust them with the proper supplements appropriately.
To prevent MBD and keep it away once it's corrected you need to have the D3, vitamin A, phos, calcium in balance. It's recommended that you use a phos free calcium powder lightly at all feedings but one a week and on that one feeding alternate between a phos free calcium/D3 powder and a vitamin powder with a prEformed source of vitamin A lightly.
Exposure to direct sunlight or a UVB bulb will allow the chameleon to produce the D3 needed to be able to use the calcium in the system. We use the D3 twice a month just as insurance..but you have to be careful with D3 from supplements because it's fat soluble and can build up in the system and lead to problems. Vitamin A from prEformed sources are also fat soluble and can build up so we need to be careful with that too. You don't have to worry about prOformed sources of vitamin A though.
Once the bones are strong again, the liquid calcium can be discontinued but the rest of the supplements should still be used.
Diet for egg laying...once the female is almost full grown, she should be fed no more tha 4 or 5 crickets two or three times a week...or other insects of equal caloric value. His will slow down or maybe even stop the egg production.
You said the chameleon isn't eating...this could be partly due to the MBD...it affects the muscles too so digestion, movement through the intestines can be slowed. Hopefully that's all it is.
Hope I didn't miss much. I'm sure someone will catch me up if I did!