Her attorneys are not very good or she is not listening to them because no, if an act is unconstitutional, not only does she not have the power, but she never had the power. The vow to find other means violates a principal called collateral estoppel. She cannot relitigate the same set of facts, and all legal arguments as to why she had these powers needed to be raised before the courts or she waived the argument. Sure she can ask for a rehearing, but only to point out an error that the court made, not that her lawyers made, if any. And she can't act like she won or will win when she lost. Rehearing by the same court is rare and you have to provide clear arguments that the court made an error in its opinion that would affect the outcome.
But she has enforcers - presumably law enforcement - who are still making sure her edicts are carried out. Traditionally, public humiliation in the media would make a dictatorial politician back off after a court loss, but when the media agrees with a dictator's dictates, that does not happen.
Actually the state Supreme Court ruled she did not have the authority under two specific laws to extend the emergency after April 30 (court was asked by the 6th circuit to rule on the question).
So Gretchen says fine, I’ll impose the same regulations under different laws which I will find to fit. And I have 21 days to find new authorities because the Michigan Supreme Court ruling doesn’t take effect until then.