Howdy Norbert,
Your wife can add your calendar account to her iPhone. In Settings > Mail, Contacts, Calendars under Accounts select Add Account. Enter the same account information that you have in your computer or iPhone. The iPhone manual has more information about setting up a Calendar account, see page 79 -
https://manuals.info.apple.com/MANUALS/1000/MA1565/en_US/iphone_user_guide.pdf
You may also want to consider setting up Family Sharing which among other things sets up a family calendar for a group. See this article for more information about Family Sharing -
Family Sharing - Apple Support
Thanks for using Apple Support Communities.
Best,
Brett L