Login to ST using iPhone

Logged out of ST on my android phone and my wife’s iphone. Logged back in to the android without incident. Logged in to my wife’s iphone and get a screen stating 2-factor authentication is required. A verification code has been sent to my Samsung phone/tablet. Not that I can tell. I get a message on my android phone from “Samsung Experience Service” stating '“New sign-in attempt.” No code, just the text.
where do I get the verification code? Any way to avoid needing the code?

You can change it from your Samsung account at https://account.Samsung.com

Do you intend to login on her phone and let her use the ST app permanently?

yes. Same devices. Permanently

If you intend on using presence, it might cause issues.

The link you provided worked perfectly. Thanks.