I am taking a guess that "Zenouska" is a pet form of "Zena" or "Zenobia", meaning "given life by Zeus". As "ouska", "uska", etc. are known Slavic diminutives. (Annuska being a pet form of Anna, for example).
I'm also going to guess that "Pomeline" is a French form of Poma, made popular the Catholic Saint Poma and meaning "apple", and derived from the name of the ancient Roman goddess of fruitfulness, Pomona.
And, yes, "Maguy" is a French diminutive of "Marguerite".
For ref. See:
http://www.asiaflash.com/prenom/prenom-histoire.php?topic=2&prenom=marguerite
-- Nanaea