Welcome Ab51alf,
Thank you for using Apple Support Communities. Based on your post, you'd like to know if your wife can use her Apple ID on your Mac. We'll do our best to help out.
You can create another administrator account using these steps: Set up users, guests, and groups on Mac
(Select the operating system at the top. If you don't know your current version, go to the Apple menu > About this Mac.)
Then you can use the Apple menu > Log out, to get out of your user and log in to her new user. Once she's signed in, she can sign in to her Apple ID with the following: Sign in with your Apple ID and iCloud with: Set up iCloud on your Mac
She'll then have access to her Apple ID and iCloud account data.
Let us know if that solves this for you both, cheers.