Android 5.1 not hit your device yet? No worries, since below you’ll find all the download links to the OTA files in order to manually update your Android device.
Android 5.1 Lollipop OTA update links
Nexus 7 (2012, Wifi-only)
The OTA will be bound to hit your device shortly, so if you’re not comfortable with sideloading and flashing files then hold tight and wait for the notification on your device.