The name Ahuva does not appear in my book because I never met it in any source dealing with the corpus of traditional Ashkenazic names. Moreover, it does not appear even in my current database of traditional names used by various groups of Ashkenazic Jews (Sephardic, southern French, Italian, Middle Eastern, Maghrebi, Romaniote). If my memory is good, I suggested the genesis of Ahuva as a calque of Yiddish Libe in a personal communication (answering a request by someone). If you run a search in Yad Vashem name database
you'll find that almost all references correspond to Poland and Lithuania and very often the person (usually born already during the 20th century) is called Liba Ahuva or Ahuva Liba. Curiously, the list includes Ahuva Alboher from Monastir (now Bitola, N. Macedonia). Maybe, in this case we deal with a calque from the Judeo-Spanish given name Amada. JewishGen database refers to a very few persons with the given name Ahuva and always in the inter-war Poland only (Wilno / Vilnius and its area).
By the way, נאהבת does not appear in the four volumes-"Lexicon of Jewish Names in Late Antiquity" by Tal Ilan.