Could some please help

My partner and I are going to be getting married soon however I have always had this burning question in my head since we first got together. My partners mum died of cancer and I never got to meet her, she is a legacy in his family. I feel unsettled marrying the love of my life without knowing if she approves. I have tried in many occasions to connect with her but with no success. My mum also is currently unwell with lung cancer. I hope someone can help thanks!