Can iPad be hacked if password's security is questionable?
Assuming you have the Find my iPad enabled, one can use that feature (from another device while knowing your password) to lock it remotely.


  Activation Lock.
  
  Activation Lock is designed to prevent anyone from using your iPhone,
  iPad, or iPod touch if you ever lose your device. It starts working
  the moment you turn on Find My iPhone. From then on, your Apple ID and
  password will be required before anyone can turn off Find My iPhone,
  erase your device, or reactivate it. This can help you keep your
  device secure, even if it’s in the wrong hands.