She tried to make herself believe that in this way she would be doing a good deed.
Upon the whole, she thought that if Mr.Glascock should give her another chance she would accept him.

And he had distinctly promised that he would give her another chance.

It might be that this unfortunate quarrel in the Trevelyan family would deter him.

People do not wish to ally themselves with family quarrels.

But if the chance came in her way she would accept it.