What type of feed are you using?
Is mom on a supplement?
I feed my chinchillas Small World Rabbit Feed Complete Rabbit Pet Food, which is $8 for 25 pounds from Walmart. A lot of people recommend Mazuri chinchilla food but I prefer Small World for the following reasons:
Mazuri and Small World Rabbit Feed have very similar ingredients. Here, here's a link to the Small World Rabbit Food
http://www.walmart.com/ip/Small-World-Rabbit-Feed-Complete-Rabbit-Pet-Food-25-lb/10323572
Ingredients: "Dehydrated Alfalfa Meal, Wheat Middling's, Roughage Products, Soybean Meal, Feeding Oatmeal, DL-Methionine, Yucca Schidigera..." and then a whole lot of vitamins.
Guaranteed Analysis:
Crude Protein - Min - 16.00%.
Crude Fat - Min - 2.50%.
Crude Fiber - Min - 15.00%.
Crude Fiber - Max - 20.00%.
Calcium - Min - 0.75%.
Calcium - Max - 1.25%.
Phosphorus - Min - 0.50%.
Salt - Min - 0.25%.
Salt - Max - 0.75%.
Sodium - Max - 0.30%.
Vitamin A - Min - 3,000 Iu/Lb.
Here is a list of Mazuri's ingredients: "Dehydrated alfalfa meal, dehulled soybean meal, wheat middlings, ground soybean hulls, ground oats, wheat germ, dried beet pulp, cane molasses, soybean oil..." and then vitamins. Info from
http://www.mazuri.com/tabstemplate-4.aspx
The Mazuri brand food actually has a lot more sugar (dried beet pulp, cane molasses) and oil (soybean oil) than the Small World Rabbit Food.
Guaranteed Analysis
Crude protein not less than 20.0%
Crude fat not less than 3.0%
Crude fiber not more than 18.0%
Calcium not less than 0.75%
Calcium not more than 1.3%
Phosphorus not less than 0.50%
Sodium not less than 0.10%
Sodium not more than 0.40%
Moisture not more than 11.0%
Ash not more than 9.0%
I give my chinchillas fresh hay, sticks from outside, cheerios, willow wreaths from the dollar store, grape vine wreaths from the dollar store, cardboard boxes, unvarnished wicker baskets,quaker rice cakes, unbleached loofa gourds, and sometimes a pita chip like once every few months. They have salt licks and those bird calcium pineapples in their cages. I also have recently given the chinchillas rawhide because no, it's not meat. I'm sure chinchillas stumble across dried up carcasses in the wild. They didn't evolve in a bubble. If they want to eat dried skin, they can. It seems more natural to me than depriving them of it. (I'm sure you're all going to attack me for it, though). I've given them a bread heel once or twice, too.
Things I don't give them: Fat. Sugar. I don't feed them dried fruit or oily foods. I don't think they eat much of either in the wild.