I want to let a grandchild use my iPad for 4 months. I am considering erasing the device and then restoring after she is done using it. Is there some way to set up a second user on an iPad?

Sorry but no; iPads are single-user only.

I’m confident that some of our “backup gurus” will ring-in shortly on that part of your question.

However, you DO want to perform the following steps “both ways” when transferring:

What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

No, you can not set up a second user on an iPad. They are single user devices. However, if you would like to backup the iPad and then restore it and let them sign in using their own AppleID you can do this. If you’re worried that things haven’t been backed up to your iCloud you can make your iPad manually backup and it will give you the most current backup of how it is now. To do this, make sure the iPad is plugged into power, go to Settings > and then click on the top where it shows the name of the account owner of the AppleID. Once in there, click on “iCloud” and then in there you’ll see “iCloud Backup” once you click on that, you’ll be able to click “Backup Now” and it will back up your device as long as it is connected online.

If you really want to back it up and create an image of the iPad as it is now so you can then bring it back to the exact way that it is setup now, you can back it up to a MAC or a PC. I haven’t done it on a MAC in a long time so I don’t know exactly where you’ll see it on the computer when you plug it in, but once you select it, you’ll be able to back it up there. If you are using a PC, you need to download the latest version of iTunes. Once you open iTunes then you’ll plug you iPad into your computer in the same manner. Once plugged in, in iTunes you’ll see the device listed on the left hand side. You can click on that, and you’ll get options as to which you can click on backup and it will save the image of your iPad. Once you get your iPad back, you can restore it again, and then select restore from backup and it will have you plug it back into the computer that you backed it up on and restore it back to the way that it is now.