This had some of the elements of my favorite type stories- adventure in a foreign country. Written in the first person and narrated by 12 year-old Felix (Felicia), she is in Spain accompanying her mother on her honeymoon. Don, the new husband is okay but with him came a stepsister, 12 year-old Amy, and a younger stepbrother, Phillip, whom Felix describes as a sniveling brat. Felix and Amy do not get along at all. Felix is fascinated when they meet beautiful Grace, who describes herself as a "citizen of the world" and wants to be just like her. She can't help herself bragging about all they own back home in America, even though most of it is exaggeration. Amy is disdainful. The parents, wanting to be alone, agree to allow the three children to go off with Grace in her battered car to see windmills. Yep, they're kidnapped by two ruthless men, who are demanding a huge ransom for the three children. Their plight is pretty scary and both Felix and Amy grow up a lot before they finally get back to their parents.
Do You like book The Spanish Kidnapping Disaster (1993)?