Outlook and Calendaring - Need Set Up Help

Windows 10 update trashed wife's icloud calendar we had synched to her outlook calendar. She likes Outlook very much but does not want to use iCloud for the calendar. Can we use google?

In short, please tell me the best way for her to input events into outlook on her laptop, have that backed up on line, and I'll be a real hero if those entries end up on her iphone too. And if I can get entries put into her phone to show up on her laptop automatically, I may get lucky.

Many thanks!