leffeboy is right – and the variation between saxes ispotentially greater than trumpets because there are so many variables
if you can get a sax player to go with you then this would be a bonus, but a dodgy reed won’t help so get her to go through the reed box and take one that she can play easily on
[edit] get her to take the mouthpiece, this is also a big variable as it will take time to get used to a new sax and new mouthpiece at the same time, so same mouthpiece will allow her to pick the sax with more confidence
incidentally is there a specific reason for a soprano? you will get more bang for your buck if you get an alto (but I can imagine if she has small hands or struggles with the weight then it’s the right call)
let me do a bit of research…. Yamaha’s are never a bad buy (Mrs Ed has a yamaha baritone and it’s really nice, I have old Conn tenor but wouldn’t recommend vintage for learners btw)