Talk to the guard at 3 o'clock position in Lighthalzen to get into the Slum district. (There is a high chance that he will stop you. Just keep talking to him and eventually you can sneak in while he fall asleep on duty.)
Go up north to the hill and help the boy. He needs 1 Royal Jelly for his sister. After you bring him that, he will ask you to bring him some items to make the baby pacifier.