Setup new iPhone without access to old phone

The normal purpose-built “fallback” method for this very situation is to receive the 2FA verification code - now needed to setup her new device - via the pre-configured “Trusted Numbers.”

The specific Trusted Number to receive the code is individually selected via the “Didn’t receive code” URL … located on the page where you normally enter the six digits.

See:

Get a verification code and sign in with two-factor authentication – Apple Support (AU)

Additionally … if the phone falls into the hands of a ne’r do well:

WARNING: Going forward - in the coming hours, days, weeks, or even months - EXPECT messages from the thieves, usually claiming to be Apple (or sometimes the police) which attempt to phish your personal info so as to be able to break into your phone and/or AppleID.

These are criminal attempts; although they can appear VERY, VERY “official,” polished, and convincing.

Disclose NOTHING and do NOT follow any links they might contain.

Absolutely DO NOT EVER provide ANY of your Apple credentials (AppleID, AppleID Password, or Device Passcode) in response to these messages.

They are NOT from Apple or from anyone else legitimate.

AppleID credentials should only EVER be entered via trusted hardware from which you have browsed to a secured Apple URL completely “independently.”

Well that’s unfortunate as you seem to have somehow fallen into the “Account Restoration” abyss.

Not sure how you can extricate yourself from that other than by contacting Official Apple Support …

In the immediate interim, she can have her number transferred via eSIM to another device … to at least get her phone number “up.”

If you have an Xs / Xr or later, she can even use your Dual-SIM device as a stop-gap.

I’d also think that she should be able to setup a new “temporary” AppleID on the replacement phone … on which she could at least have her phone and SMS services restored …

…. while her original AppleID access is sorted.

Again, I’d suggest setting up a “temp” AppleID and getting at least her number and SMS working on the new phone.

I fear that you might be facing a lengthy “uphill slog” on her original AppleID restoration. 😕

I suspect that somehow “restoration” was invoked before the trusted number was used. Anxiety from loosing a phone sometimes makes our behavior “click first, think later.”

The REAL lesson for the future is practice …

… ACTUALLY PERFORM the “Lost Phone Drill” under controlled conditions to eliminate - or at least reduce - the anxiety when doing it for real.