seriously, if she wants you to install something for her tell her to let you do it you're way. You shouldn thave to sneak something anywares. Its a free install, she asked you to do it now if she asked then she needs to trust.
I install about 5-10 Audio setups a week. I do them for free for high school students, (im 17) now when they cometo me goign "Dude! i hear ur the best wanna hook up my system and how much?" I say free then they show up and are liek you knwo what ur doing? 500 times through out the process then there like trying to tell me how to do something. And I explain to them that if they came to me wanting my help just sit back and trust me cuz if you wanna question me then go have a 50 dollar installer do it.
Explain to her you are doing it the right way and to trust you cuz its a free job.
Sorry had to type something. Personal probs.
~Chris