Kitten won't clean herself

Hello,
I have a 4 month old kitten who doesn't clean herself. And she's got long hair!
She seems to be completely unaware that it is what cats should do and waits for me to bathe her... though she's not crazy about bathing time.
Is there anything I can do to encourage her to lick her fur clean?
Her nickname is pig pen...

How old was she when she was taken from her momma? It sounds like she wasn't taught to clean, usually happens if they are separated too quickly.

Do you have another cat? One of mine was too young when we found him and our other cats took over rearing him. Maybe wet his fur down and see if she gets the idea while cleaning the water off?