Hi !!!
Yes it has the same root 'Z-Y-N which means 'beautify'.
Despite its floreal meaning I can say that
Zaynab is a very religious name while Zeina isn't.
Augusto Aurelio Bruno Filippo Flavio Leone Luigi Stefano Valerio
Alba Anastasia Angelica Cassandra Dafne Diana Flora Ginevra Lavinia Luna Morgana Perla Rosa Serena Stella Susanna