thankyou very much :)
can nintendo tell if a pokemon's parents where caught using a wild pokemon modifier?
The answer is no. In fact, I doubt they could even tell if it was hacked as long as all the stats, movesets, and "met at" page are all in order.
Personally, I'm still too afraid to try outright hacking because I could be wrong and don't want to get kicked out of Worlds (that would be such a stupid waste for nothing :/ ), but when I was at Nationals, I talked to some dude from TPCI (not just one of those ridiculous "assistants") while he was actually hack checking my, and Siddarth's pokes.
Long story short he basically said to me outright that the device they use can check the IVs, EVs, Moveset, and "met at" of any of your pokemon that you have in your cartridge against a list of what's allowable.
He kind of turned the screen away from both of us while he was using it, but I did see that it came up in the form of a "download and play" program like those Wind Waker minigames or whatever, and then he just pushed some buttons looked at it while he was explaining it to me and goes "Uh, oh. We've got a problem. Your pokemon failed the hack check. You've got too few pokemon in your party." And I was like, "What?Q!?" And he was like "Nah! Just kidding you passed! :D"