Mind you that we find out at the end that the entire movie took place over a four week period. OK, he's a quick study. Name an adult who learned to read in two weeks. This particular guy would have taken that long to learn the names of the five vowels. To show that she's ready, Portman takes one of Reno's guns and fires it repeatedly down at passersby.
Nothing ever comes of it.
No police, no neighbors. Nobody checks it out, Reno teaches Portman how to be a sniper from the top of the Plaza Hotel, firing at joggers in Central Park, about five hundred yards away. He just pops it on there, she looks through, and hits the guy in the chest. Then they calmly pack up the rifle and leave. We hear that Portman's school in is Wildwood, New Jersey, but she is able to get there by taking the skyride to Roosevelt Island.