Echoing picking the 13 for best bang for buck. It’s a great phone and as for the other phones on your list you wouldn’t be missing out on any features.
If the finances aren’t the biggest factor in your decision, and if your partner is certain that they still want a huge phone in their hands then go with the 14 plus instead. Big phone = better battery, which I’m sure is an issue for them with their 8 plus currently.