Some people object to marriages between Catholics and Protestants.

You are a Catholic--" No! She could not trust herself to refer to him directly; she went on to the next sentence.

"And there might be some other reason," she resumed.
"Do you know what that is ?" Carmina asked.
"No more than you do--thus far." She spoke the plain truth.

Thanks to the dog's interruption, and to the necessity of saving herself from discovery, the last clauses of the Will had been read in her absence.
"Can't you even guess what it is ?" Carmina persisted.
"Mrs.Gallilee is very ambitious," the governess replied: "and her son has a fortune of his own.

She may wish him to marry a lady of high rank.