Hello and welcome to Apple Support Communities, Photohelp_thanks.
If we understand your post correctly, Photos has mixed up two people as one in your Photo Library. We’d like to help.
We see you were viewing "Organize and find your photos on your iPhone, iPad, or iPod touch - Apple Support" and it did not resolve your issue.
To help Photos correctly identify the people follow these steps:
Fix mixed-up names and faces
If you notice that there's a photo of someone in a collection that's misidentified, you can remove it. Here's how:
In the People album, tap the person.
Tap Select, then tap Show Faces to focus on just the person's face in each photo.
Tap each photo that isn't of the person.
Tap the Share button
, then tap "This is Not [Name]."
From the article: Use the People album in Photos on your iPhone, iPad, or iPod touch - Apple Support
Let us know if that resolves this issue for you.
Thanks for using the Apple Support Communities.