unfortunately for that theory, infection is done by needle like we've seen in the game, not by biting like in the other RE. its not common to see a daughter give her father a needle, people will definitely see that and know something's up.... he's the president, security around him will definitely be tight.
we've seen two types of infection in the game. in the case of the villagers its involuntary, and so you see their behavior is very odd. in Salazar and Krauser's case its voluntary, and so you see they can still act normal and have control. for Ashley it will be involuntary, so the plagas will have to try its best to act like the normal Ashley. and as we've seen in the villagers the way they walk, run, move is different from normal people, the best the plagas can do in acting normal as their host is not good enough.
also like mentioned. infection is done by needle. infecting the white house is going to take a lot of assistance Ashley doesn't have, Ashley is sent back, not the whole village/castle/island army. how to do it? one by one call the entire white house into her room? that just screams suspicious. successfully infecting her father won't change much---> suspicious act is suspicious.
we should just agree the story writers for this game didn't think over their world domination plan carefully.