Backing up a locked iPod Touch

My granddaughter received a new iPod Touch for her birthday and immediately began filling it with songs an apps from iTunes. She never backed it up after I activated it on iTunes. Claims she didn't know how. It is now locked because of a forgotten password. She wants grandpa to unnlock it without losing any of her material. How can I do that. I know how to restore it but I don't know how to do a sync or backup from a locked device.