Para describir a las personas

Cariñoso/a: The book translates this as "loving," which is a good translation. However, it doesn't necessarily mean romantically loving. "Affectionate" is an equally good translation. By the way, this is considered an extremely important characteristic in little children.

Mimado/a: It probably says something about Anglo culture that our only translation for this is "spoiled," with all its negative connotations. Mimado does mean spoiled, but it comes from the verb mimar, which means to coddle, pet, fuss over, or dote upon someone. Depending how you say it, a child who is mimado can either be "spoiled" or just very protected and adored. (Watch for this word in one of your upcoming episodes of Destinos when Angela and Raquel are discussing Raquel's relationship with her parents. Angela uses it to describe Raquel, and Raquel is not at all offended.) If you want to say that a child is spoiled rotten and obnoxious, you'd use engreído/a (which implies conceit,) consentido/a (which means s/he's been given everything s/he wants), or malcriado/a.

Molesto: A good example of ser/estar changing the meaning of a word. Está molesto means he's upset, annoyed; Es molesta means she's annoying.

Verbos

Extrañar/Echar de menos: As the footnote says, this is "miss" as in "regret the absence of someone or something." If you want to say you missed your bus, your plane, your chance, etc, you use the word perder. (If you're freaked out by the idea that "miss" and "lose" are the same word, think about the expression, "You snooze, you lose.")

Heredar: This does mean to inherit; it also means to leave an inheritance to someone else. Context clarifies.

Más relaciones familiares

Benjamín: Not everyone accepts the term benjamina. To some people benjamín specifically means youngest son.

Gemelo/a: Usually this applies to identical twins. There's also the word mellizo/a, which works for any kind of twins, identical or fraternal. Interestingly enough, there's the word trillizo/a, but no commonly-used words for multiple births beyond three. (These terms didn't exist in English, either, until the Dionne quints.)

-astro/a: This suffix has different connotations in different areas. In Spain, hermanastro/a, madrastra, padrastro are the standard terms. In some parts of the Americas, though, especially conservative areas (like the US-Mexico border, for example), these words can be faintly or sometimes more than faintly offensive. Particularly hijastro/a can imply illegitimacy. In those areas, if you're close enough to your step-siblings to consider them relatives, you call them hermanos; if not, they're the children of your parent's spouse. For stepchildren, you may occasionally hear the word entenado/a.

By the way, there's no common word in Spanish for step-grandparents. Again, if you're close enough to your step-grandfather to consider him a relative, he's your abuelo; if not, you describe him as "el padre de mi padrastro" or "el esposo de mi abuela" or whatever the relationship is.