The picture is not working. Wet or a look like the fur got wet previously can be lots of things. Hitting a water bottle, getting urine on them especially with other chinchillas in the cage, and just friction of some repetitive boredom behaviors can make a clumpy appearance. If it's not anything serious a few good dust baths should fix it. If fluid is potentially leaking out of the nipples the female should be watched for redness, swelling, and fur chewing that can be the result of mastitis.
Kits should start weaning at 4-6weeks. If the process has not started by 8 weeks they will need some help. If they are eating solid food males should be separated at 8weeks. This is another important time to check weights frequently. They should keep gaining 2 or more grams a day after being separated from their mother.