One lesson learned: activate the Guest account and if your niece comes again, let her use that. Don't tell her your own password. And certainly don't tell her the password of an administrative user. Same for other guests, of course. Much safer.
Now I would try system restore back to before your niece came. With a little bit of luck, that works.
My niece came for visit. She is 15. I allowed her to use my computer. A few days later I seen programs on my computer and stuff attached to browser. I tried to remove but they wouldnt allow me to. Zone alarm, Free games..a few others. After trying to remove i would try another program but it would say i couldnt because it was busy removing another program. Even an hour later. My vpn wont even log on. Ive used revo uninstaller pro to remove the programs and ccleaner to also clean. Programs appear to be gone however im still unable to remove programs and unable to access my vpn.
Can someone please help me? Id be so appreciative.