I would recommend starting her off with an Ace 250.
Lower cost than most detectors but still a nice unit, and will allow her to get into the hobby. If she really gets into it, then you can look into getting a detector that costs $1000’s, but I wouldn’t start off at that price.
She will also need a pinpointer detector. They are pretty essential.
Are pull tabs from coke cans etc. still a big problem? Back when I was using my Whites quite a bit, those pull tabs were really hard to tell from a coin. Maybe they have all corroded by now.