User blog comment:FairyRaven/Fairy Tail Chapter 427: Pitched Underground Battle, Review and Commentary/@comment-24784846-20150406134543/@comment-96.24.244.24-20150407111259

Her stardress works with all her keys not just her Zodiac. The down side to Lucy's stardress is that you either get feats from Lucy with the stardress fighting or her celestial spirits fighting. Avatar is far rom strong enough for both to be needed. As you can see with this chapter her going Virgo form wasn't needed as Virgo could have done the work alone like she did when Lucy faced o against Naked Mummy.