So, where is the sister, did I miss something?

Apparently there is another story that focuses on the sister

http://www.mangago.zone/read-manga/the_spanish_billionaire_s_pregnant_wife_virgin_brides_arrogant_husbands_3/

http://www.mangago.zone/read-manga/the_ruthless_magnate_s_virgin_mistress_virgin_brides_arrogant_husbands_2/
She has a brother too, I learned

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