NO you won't see much of a difference or horsepower gains. the only other way i would imagine you'd see much gains is if you

modify/get a bigger throttle body
bigger intake manifold
at least 3 inch piping on CAI
and spend decent money and get a K&N filter


thats the only way i can see much gains on a cai, and that comes from experience on helping my cousin with his b18c1 swapped civic si hatch. he did all that i listed there PLUS full catback with 3 INCH piping straight to the back and only gained around 12 hp. alot of people mistake alot of the principles of how engines work, including me. when i first "got into cars" i was thinking small. CAI, putting a "aftermarket" muffler on stock pipes thinking i was getting "speed" . until someone introduced me to the wonderful world of turboes. like orion said, if she wants REAL HP gains she might want to look into these not all at one time of course, unless she has alot of money:

cam gears
camshaft(don't know how that will work with the vvtl-i)
aftermarket throttle body
full exhaust(and i mean full, not just headers and a tailpipe)
piggyback ecu system greddy emanage is pretty good for decent tuning(again i don't know how this will help or hurt the vvtl-i)
lighter flywheel, pulleys

i don't know how much HP that will get you, but its way more practical than sticking a whole bunch of rice mods on a nice car.