The spelling of the name "Libby Houston" can be explained using IPA phonetic transcription. "Libby" is pronounced [ˈlɪbi], with a stress on the first syllable and the vowel "i" pronounced as "ih" as in "in". "Houston" is pronounced [ˈhjuːstən], with a stress on the second syllable and the "h" pronounced strongly. The vowel "o" is pronounced as "u" as in "uh" and the final "n" is silent. Therefore, the correct spelling of this name in English is "Libby Houston."