If you still need the iOS 14 beta IPSW this year, you can expect to find these files in Google Drive folders shared by people on Twitter or on select websites.

In this folder you’ll find an iPhone restore file (ending in .ipsw) dated sometime in late June 2010. Copy this file to your wife’s Mac.

Then select your device in the Finder sidebar, hold down the Option key, and click on the Check for Update button. Open the IPSW file on your computer and follow the prompts.