Q: My little sisters deleted my apps store how do I get it back?

Go into settings, general, restrictions and see if she restricted it, which makes it invisible. You cannot delete the app store so it's there somewhere.

If it wasn't restricted....

Swipe from screen to screen to look for it. It could be buried in a folder on another screen. If you do a search for the app using Spotlight, you will see what folder it is in if you look to the right of the app name.

You can also reset the home screen layout and the icon will reappear - but the home screen will return to the way that it looked when you first activated your iPad.

Settings>General>Reset>Reset Home Screen Layout.

...

Check in Restrictions... Settings > General > Restrictions

Understanding Restrictions  >  http://support.apple.com/kb/HT4213

2)  Check in All Folders and on All Pages/Screens...

3)  If no joy... Settings > General > Reset > Reset Home Screen

Note:  Pre-Installed iOS Apps cannot be Deleted.