After few dramas with children who made too many attempts to crack my iPad password, resulting our iPad to disable (unfortunately the only solution is to restore it in recovery mode), I finally found a way to restore it easy way.
Now first i make sure I backup the iPad. It won't let me update and restore so I had to do the full recovery restore. I just backup to be safe but I later found out I can't restore from backup with the latest (today) backup. It will only select the 2nd last backup.
This is what I tried and works. If you plug in your iPad to your PC and click the iPad icon on iTunes, then you'll see the various folders on left side panel e.g. summary, apps, movie, music. Click apps then you'll see list of apps on the window. Scroll to the bottom, there is a separate apps window with lesser apps. Usually my music and movie apps will show here. Then you click Minecraft icon (hopefully yours will show), the on the right hand side panel it'll show the folder e.g. games, internal. I select both and click "save to" then I saved them to my download folder (you can select wherever as long as you can find them).
After that I do the full recovery restore. You can google how to do recovery restore, there are plenty of videos and instruction on that. Note: You can skip the recovery restore if yours works fine. Now, when I sync my iPad, I go back to the apps window on iTunes and find the minecraft icon same way as before. When you look at the bottom of right panel window you'll see "add to" and "save to", click "add to" this time. Then find that folder that you have saved before and click it. It will asked if you would like to replace the folder with same name and I click yes.
My son is ecstatic that he didn't lose his world that he worked months on. And I once again become the hero mum :D