in silent hill 1, the town is in absolute berserker mode because Alessa is being forced to draw her other half, Cheryl, back. As such, there are all sorts of monsters about the town that would not typically be there which can be seen as a result of her psychic projections.
on the other hand, because of these psychic projections, the strength of the cult has grown and the faith and fervor may have made the town a bit weird. Consider the fact that Harry and his wife, at the beginning of SH1's cinematics, pick up a baby who then becomes Cheryl. The fact he seems pretty willing to head back in its direction says to me it's something of a quiet tourist destination.
now flash forward to silent hill 2, town seems abandoned, locks are broken, and yet this little girl runs around with no real problem. My theory is that she heard about Silent Hill from Mary and after Mary disappeared with her husband, she thought that maybe he had finally taken her out there. So I think it's possible she ran away from the orphanage to try to find her. She pops in the apartments because that was James' old address before Mary got sick (Mary let her come along once, but she couldn't remember which apartment it was. It sort of explains the weird James model body in the clock room.
She goes to the bowl-o-rama, thinking maybe Mary went there with her husband for some fun. (she was wandering the streets earlier trying to find where Mary was, and doesn't like James because she assumes he lost her somewhere.) When we see her in the hospital, it's actually because the police were called at the bowl-o-rama and they found out she was a child missing from the orphanage a town over.
They decided to keep her at the hospital rather than the station because she seemed more comfortable there and they figured Nurse Rachel could find her there easily. However, at some point she escapes and starts to harass James (who the other nurses don't see because he's on a different level of Silent Hill). Because she sees no monsters, she sees no problem with locking James in a room because she thinks he's being a jerk.
Finally, we see her in the hotel because Mary told her about it. Seeing that it's mostly a burned wreck, she's scared that Mary may have tried to go inside anyways, and relies on James to try to find her so that she isn't in danger. She finds him sitting in a ruined room and asks if he's found Mary, and gets mad at him after finding out that he killed her. She gets angry at him and leaves the burned husk of a hotel, and what happens to her depends on the ending (for all non-Laura endings, she finds a policeman to take her home, upset at Mary's death.)