In all fairness, GTAIII is a mature-rated game, and as an older gamer, I think it's good to see parents actually take an interest in what their kids do or don't play. That's a rarity, especially given the media trend to ignore age ratings on games in their bid to blame whatever the latest controversial game is for some tragedy.
Is GTAIII a violent game, yes it is. Granted, it's aged a LOT since the initial release, but it is still a violent game at its core.
In terms of the "prostitutes", you can go through the entire game without ever actually "dealing" with any ingame at all. However, to finish the story mode, there will be a lot of shooting, destroying cars and - in general - chaos caused directly by the player.
