Hello super sophie,
It sounds like your iPhone spells names with different spellings than desired. You could add the desired spelling of the names as text replacements.
When you have a free moment, check out the link below to learn how.
How to use Auto-Correction and predictive text on your iPhone, iPad, or iPod touch - Apple Support
Next, we’d like to show you how to perform the recommended troubleshooting steps via the link above. Please click to open the link, then read through the steps in the section titled "Set up text replacement."
Set up text replacement
With text replacement, you can use shortcuts to replace longer phrases. When you enter the shortcut in a text field, the phrase automatically replaces it. For example, you could type "GM" and "Good morning" would automatically replace it.
To manage text replacement, tap Settings > General > Keyboard > Text Replacement.
1. To add a text replacement:Tap the Add button .
2. Enter your phrase and shortcut.
3. Tap Save.
4. To remove a text replacement:Tap Edit.
5. Tap the Remove button , then tap Delete.
6. Tap Done.
We recommend the steps above because they will show you how to use text replacement to get better results with the spelling of names.
Another thing you could try is resetting the Keyboard Dictionary to try and change to the desired spelling.
You can do that by navigating to Settings> General> Reset > Reset Keyboard Dictionary.
Thanks for using the Apple Support Communities.
Cheers!