Welcome Taz ... you are a good Dad to be checking this issue. Simply put, in a situation posing a threat to human safety, a GFCI will trip instead of shocking you because it checks the hot (black) and neutral (white). This functionality is not affected by the presence of a ground.
If you buy a GFCI breaker for your service panel circuits it will monitor all downstream activity for each circuit. The GFCI comes with a sticker to be specifically affixed when the gfci has no ground. Put on those stickers!
Also, remember that the mere presence of a three-prong outlet does not guarantee a grounded receptacle.
Want to really protect here house? Retrofitting two wire with GFCI's plus the usage of a whole-house surge protector is a fantastic alternative to rewiring the whole place even though it will not e a "grounded" house.