Her own love for Jervis made her hesitate about allowing him to bind himself to a life of poverty, or at least a life of continuous struggle, such as marriage with a portionless wife must bring.
But Jervis was only one consideration.

There was Mary also to be thought of.

And then it flashed upon Katherine that Mary had even more claim upon her than Jervis.

Ever since 'Duke Radford had been stricken down, robbed of memory, of understanding, and the power to think and act for himself, Katherine had carried her father's sin as if it were a wrongdoing of her own.

He had implored her to expiate it if she could.