Ipad password how to fix and complain

So I went on vacation with my family and my mother have an Ipad air 2, which she left at home, but when she got home she noticed that it had ran an update or something and had then added a password to it. Normally she had a 4 digit password with the 4 dots that she used to unlock it with. But now it is asking for another one and it is just a textbox.

Me and my brother usually help her with it, but none of us have any clue what the password is suppose to be or where it comes from, besides maybe from an OS update?

She took it to a computer shop which wanted money to restore it. But since she planned and already have bought a new one, she gave it to me.

And have tried to restore it or do a factory reset on it using Itunes, but that just get stuck so that just perfect.

Because even though it is not technically my ipad as she got a new one, it is beyond me and furious to say the least, how on Earth something like this is possible in the first place? Luckily she only uses it for emails and other stuff on the internet, so she doesn't have any local things on it that is important. But I can only imagine if she had.

Does anyone know how to fix this?