I have been cruising since 1992 and have never felt even a tinge of fear for my safety. Please don't let the media hype over a couple of incidents concern you. Many in the media love to find faults with cruising. They take something and run with it, and leave the impression that every ship afloat is rife with crime and violence. It simply isn't so. If it were, I would not be taking my 11 year old son on cruises every year - and his first was when he was 2 years old. A ship is much safer than most other vacation options.
Have a great cruise!