Yes, you are right about Catherine's will. I should have checked it again with rested eyes before posting. I'm sorry for causing so much trouble.

I looked at Elizabeth's will again (1903 - # 237), and I still see Catherine mentioned as a widow:
( The first page filmed)
KNOW all men by these presents that we Catherine Killip of Tower Rd in the town of Ramsey widow, Ann Jane Pass of Tower Rd aforesaid widow and Philip Lace of Ballachurry in the parish of Jurby ..............

And on the hand-written page signed by S. Stevenson Moore:
............ the last will and testament of Elizabeth Killip late of the Clenagh Road in the Village of Sulby parish of Lesayre spinster deceased who died on the 15th day of May 1903 at Lesayre aforesaid Catherine Killip of Tower Road in the Town of Ramsy widow a sister of the Testatrix, the executrix herein named is sworn..............

The reference to "widow" in this will must have been a mistake.