A Widnes statement said: “Sadly at 6.30pm on 10 August 2010, Christine Cullen, aged 48, died peacefully at home with her family after a long battle with cancer.
“The club sends its prayers and heartfelt condolences to Paul, their sons Josh and Scott and family and friends.”
On the field, Widnes beat Toulouse Olympique 44-30 in their last game. Assistant coach Stuart Wilkinson said: “I never felt we were in danger of losing the game.”
Victory for the hosts would put them four points clear of seventh-placed Batley.
But a win for Sheffield would confirm the Eagles’ place in the Championship play-offs.
Skipper Jack Howieson is set for a surprise return after recovering from bicep and knee injuries.
Howieson, who has been out for almost six months, last week played for the club’s reserve side.
Sheffield Eagles coach Mark Aston said: “Widnes had a good win and it won’t be easy for us.
“It will test how good this team is. We have two games to go and if we win one we will get in the play-offs.”