Grace and mercy are often confused. I can think of a million (not really) examples of mercy in the Bible, but not for grace. Mercy is showing kindness or forgiveness when it isn't deserved. Grace is an undeserved favor, though. The grace of God is that He gave us His Son. But at the same time, it's also mercy, because of what that Gift represents... His blood offers us the chance to have salvation if we choose to reach out and grab it.
Can the princess have a sister or pet (or queen mother) named Mercy?
"But Noah found grace in the eyes of the LORD" (grace = favor, which means the Lord was pleased with him)
"‘I know you by name, and you have also found grace in My sight." (About Moses ... the Lord wanted to use him to speak to Pharaoh)
"The king loved Esther more than all the other women, and she obtained grace and favor in his sight more than all the virgins; so he set the royal crown upon her head and made her queen instead of Vashti."
"And the Child grew and became strong in spirit, filled with wisdom; and the grace of God was upon Him." (Jesus)
"For the law was given through Moses, but grace and truth came through Jesus Christ."
"What shall we say then? Shall we continue in sin that grace may abound? Certainly not!" (Romans)
(Many epistles are introduced and closed with grace, as is the book of Revelation.)
"I marvel that you are turning away so soon from Him who called you in the grace of Christ, to a different gospel..."
"Let no corrupt word proceed out of your mouth, but what is good for necessary edification, that it may impart grace to the hearers."
"Let your speech always be with grace, seasoned with salt, that you may know how you ought to answer each one."
"Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need."
"Of how much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace?"
"Likewise you younger people, submit yourselves to your elders. Yes, all of you be submissive to one another, and be clothed with humility, for 'God resists the proud, But gives grace to the humble.'"