wet belly button

Hi, My cat Jess had 4 beautiful kittens on Monday and they are all doing great except one, Her belly button is wet, slightly smelly and there looks like a small hole where her umbilical cord has come off, she eats plenty and seems to behave the same as her brothers and sisters but I'm a bit concerned. She is the same size as the other kittens so I'm pretty sure she gets enough food. Jess, her mother, does lick this kittens belly button regularly. Thanks

The kitten has an infection and maybe other problems needs to see a vet as soon as possible.  Don't wait until she starts going downhill, it could well be too late then.

could be a hernia and if smells sounds like infection at the least.  ask the vet...try to get her in in EARLY am before any other cats and make sure she touches only cleaned surfaces that she MUST be on.