Chinchilla baby getting neglected-Help!

About a week ago my chinchilla gave birth to three adorable babies and since I have been tracking their weight (and their mom's). Two of them have been steadily gainning, but one of them isn't gaining much. I am nervous that he is getting neglected and I am not sure what I should do. Here is my tracker of their weight: Chinchilla Weight Tracker
What should I do? I've tried to...

Chinchilla baby getting neglected-Help!