My mother died in 1998 and left her house to her 4 siblings She gave her then husband not father a life estate in the house Would him getting married again cancel this life estate Thank you Mike Niels?

If your mother granted her husband a life estate in her will the language of the grant would need to be examined for any limitations. If there was no provision made for the life estate to expire upon his remarriage then it lasts for the duration of his life.