Welcome Kaaaaaayllaaaaaaaaaaaaaaaaa,
Thank you for using Apple Support Communities. Based on your post, you can't enable a Focus status to be shared with a specific contact.
To make sure we're on the same page here, you have Focus enabled during this time or not? Are you seeing the notification '(Contact) has notifications silenced' within the conversation in the Messages app? If so, this is that contact's focus or silenced notifications. Tapping on this and selecting 'Notify Anyway' will notify that contact of your previously sent message.
If that isn't what's happening, do you have this contact added to your Focus enabled? When you go to Settings > Focus and tap on the Focus that's enabled, then on 'Allowed People' is this contact here? If so, you'd want to remove them.
Learn more about Focus here: Use Focus on your iPhone, iPad, or iPod touch
Hoping to hear back, take care.