That’s a perfect first reaction. Seriously. Kudos.
I wish more people were as suspicious of things like this.
You can check suspicious URLs (web site addresses) using urlscan.io
It’s free.
Here’s the results for
www.messenger.com
urlscan.io - Website scanner for suspicious and malicious URLs
urlscan.io
It’s legit. It’s the web version of Facebook Messenger.
Miguel,
It’s more likely that someone cloned your wife’s account and is using the fake account to try and get in to your legit account.
Why? “Mo data. Mo money.” Is the short and most likely answer.
My thoughts/advice: once you get to the point of knowing their account/profile name, report them and block them.