To transfer contacts from iPhone to iPhone, using iCloud is the easiest method. Ensure both iPhones are signed in with the same Apple ID/Apple Account. On both phones, open Settings > tap your name > ...

If she's using the same SIM card, she can easily transfer contacts herself. If not and you're on AT&T, take both phones to a company-run store and they'll transfer them over for free. T-Mobile will ...

The newer eSIM technology, which is quickly becoming the standard on high-end phones, is safer and more convenient.