How to sync two iPhones together?

There isn't a direct way to sync two iPhones together like syncing a computer with a phone. However, you and your wife can share certain data between your iPhones using iCloud.

Share with Family Sharing:

Apple's Family Sharing allows sharing some apps, music subscriptions, movies, TV shows, and a Family iCloud storage plan. Set up Family Sharing on iPhone

Create a new shared album

1. Go to the Albums tab and tap the Add button .
2. Tap New Shared Album .
3. Give the shared album a name, then tap Next.
4. Choose people to invite from your contacts, or enter an email address or iMessage phone number.
5. Tap Create.

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