Lost notes after Mail app sync

Hi there,

iPhone 5C

In brief:

• Colleague turned on Two-Step Verification
• Gmail App kept syncing but Mail app didn't
• Today advised her she needed to generate an app password, she did so
• Mail App started syncing again, HOWEVER all notes she made since it stopped syncing when two step was turned on have been lost.
• Not in any of the accounts on there
• No iCloud account/ back-up not set up
• Notes aren't in Gmail either, last one's again, are from when two-step was turned on
• Tried power and back button restart, no joy

What are the options for getting them back? If any.

Any help is greatly appreciated.

Best regards,

Nathan