> My dads family is Belarusian but they are a mix of Ethnic Balts, Finns, Russians and Tatars.
You forgot to mention a someone from north-eastern Latvia to this list you mentioned above.
I doubt there were Finns in Belarus. Also, Lutheran Finns, Orthodox Russians , Muslim Tatars, Roman Catholic Lithuanians, Jews were unlikely to mix in the past due different religions. Exception was Orthodox/Greek Catholic Belarusians mixing with Roman Catholic Balts and Poles despite religion.
The picture you sent me of a female stating she’s from north-western Belarus with a surname common among Lipka Tatars did have a Tatar vibe about her. She looked as a Finno-Ugric of Volga-Ural region of Russia.
People who stated this particular relative of yours looks ‘Finnic’ probably meant she looks Finno-Ugric of Volga -Ural region. She doesn’t look as a regular Belarusian, Lithuanian, Estonian, Latvian or Finnish (Finn of Finland) in my eyes.