Why Exactly Does Scientologist Isabella Cruise Have Cross Tattoos?

I saw this photo of Isabella Cruise, daughter of Tom Cruise and Nicole Kidman, today.

Celebrity kids with blue hair and tattoos is nothing unusual. But a Scientologist celebrity kid with cross tattoos? That does feel a little bit weird. I would really like to know the answer to this question. I would really like to know what LRH would have to say about that.