Do not know if I consider her to strong.
You can use her, are happy with your cards. Then it´s a 6 for 6. You can be unhappy with your cards, you get rid of a unwanted card and that´s it. Real value is never more than 6 for 6 but you can increase the likelihood of drawing better cards a bit. From my understanding such cards, are kind of normal in deck building games (like Dominion for instance).
If you want to include her you have to think about 6 provisions alternatives at NG:
Peter Saar Gwynleve: 3 body, Deploy: Reset the power of a unit.
-> Success of this card is very depenent on which deck you face (typically NG)
Rico Meiersdorf: Whenever your opponent plays a unit while Rico is in your hand, set his power equal to that unit's base power.
-> Even more dependent. Porbably only lucky against MO.
Roderick of Dun Tynne: Disloyal. Deploy: Look at 2 random gold cards from your deck, then play 1 of them. -
> NG´s best tutor, can double use via Coup de Grace; great synergies with masquerade ball; but must be careful; in worst cases you do not have golds in your deck when you play him (my NG 6 provision favorite)
Traheaern var Vdyffir: Deploy: Look at the top 3 cards in your opponent's deck and move 1 to their graveyard.
-> Can seriously harm opponent when you manage to get a strong card (very likely as you draw 3). Nice synergies with deck milling; Antisynergies with deck filling (new WotW concept);
Vanhemar: Deploy (Ranged): Destroy a Locked enemy unit.
-> Synergizes nicely when you have a block intense deck/leader. But can be a 3 for 6 if you do not have enough blocker
Amnesty : Seize an enemy unit with 3 power or less. Conspiracy: Boost it by 2.Devotion: Always trigger Conspiracy ability.
-> Success heavily depends if you have valuable targets. Very risky!
Viper Witcher: Deploy: Reveal the top card from your opponent's deck and Banish it.
-> To my mind the worse Traheaern var Vdyffir
=> Maxii is the 6 provision card offering by far the highest guranteed value of 6. However I think that Roderick of Dun Tynne, Traheaern var Vdyffir and Vanhemar are usually the better 6 provision alternatives.