Note:

• 1971 is the copyright year, from library records, and it is the year given at Forgotten Books and Stories and at Amazon. The reported publisher name-form "Xerox Family Education Services" is found occasionally in Novemmber 2018 automated search of 1972/73 newspapers, not found thereafter, while "Xerox Education Publications" is common 1972 to 1976.
• "the second book in a series about Christie MacAlistaire and her brother Kevin" --Forgotten Books and Stories (blog at WordPress.com), with synopsis of the first part of this sequel

Synopsis: Set in Ireland, while two American children and their mother visit a family friend. From "the oldest gypsy" the 11-year-old girl Christie gets a quest and a protective amulet. The quest features a ghost. --gleaned from a long synopsis at Forgotten Books and Stories (above)