THIS IS WHERE I AM REALLY STUCK

When there are 2 Marys and Roberts around same area, age, marriage year etc.... The only way to solve it is.....does anyone have the death cert or info on death of Mary Roberts died 24th nov 1888 age 71 in St Dennis? They can't both of died same day!!!
It will be the one i want if i can sort that part.
Thanks guys for the imput so far
