If i have a meera in play and i put a copy of meera out of sshadow, the second meera can activate her effect of blank cards? i believe not but the strange rules of meera make me to do the question.

You're right, her ability doesn't trigger. As soon as she's out of shadows, she becomes a duplicate, and so while a "Card" left shadows , a character did not enter play (specifically, Meera Reed didn't enter play). The "Then" effect never happens.

This is specifically addressed in the FAQ p.25