Hi @Tam O Ronnoc
Welcome to the Sonos Community, and Happy Birthday!
The email address to which your Sonos account is registered does not need to match the email address to which Alexa is registered, so there should be no problems in that regard - though it will be easier to add Alexa to your Move if you do so from the Sonos app installed on your wife’s phone as it will remember the Alexa account login details. This will make no difference to your overall usability.
As for the process of adding the assistant, it’s simple enough - Settings » Services & Voice » Add a Voice Assistant » Amazon Alexa. Note that Sonos Voice Control can be added to the same speaker as Alexa, and can run at the same time.
I hope this helps.