Bypassing Ipad lock code???

My 8 year old daughter uses our old Ipad 2 for her games and movies. She hates to share with her brother so she figured out how to turn on the lock code but then forgot the code. She then proceeded to keep trying it until the ipad was disabled. We attempted to hook it up to the computer it is linked to but ran into an interesting situation. My wife's computer is a very old imac. She is still on OSC 10.6.8 and can' go any higher. She is also at the highest version of itunes she can use. When we tried to restore the imac it would only allow us to wipe it and install 8.3. When we click on it we get some error that it can't be done on that computer. I have tried to connect with my more current macbook pro but since we can't get past the lock screen I can't select to trust the computer. Does anyone know of a solution so that we can bypass the lock screen?