Shockingly is not a catastrophically one sided with Magnolia having Goildoat and Aplin who can remove themselves after attacking. It's still an awful match even with that factor.
The luck in Siana's deck is very bad, so every drive check doesn't trigger, which is very disappointing, but I admit that Siana's deck is not as flexible as Charmout
Magnolia Masque's hand size generally isn't the biggest either so most time you can't afford to discard. Maggy can somewhat get around the Bitch's bs with rearguards the remove themselves after attacking so you don't have to discard namely Aplin and the Goat but even with that factor it's still awful for Magnolia.