I used a deck of Miounne, Wedge/Biggs, Momodi, Baderon and a rare card (I think it was Terra). All the sides of the 2* cards are 7553 in some order so you can take advantage of plus in a whole bunch of ways, and same in a few others. She will definitely flip some of these cards but not only can you plus your own cards back, some of her strong cards have weak points to this (Merlwyb has a 3 and 5, Cid has a 5, etc.) After I got the hang of it I was able to win more than lose, even against her strong deck.

I think Merlwyb was a high 50s card for me in terms of order I acquired them.

Hope this helps if you haven't already gotten the card, good luck!