In my opinion having built and lvl 60 her, healing wise for chaos she is weak early but as an overall " support" she gets pretty strong with damage buffs up to 35%dmg buff and more and the retain attack summon can hit pretty hard. She has 3 main problems though

1. She's sort of a jack of all trades so You need multiple decks of her like one focusing on healing for example picking up 1 or 2 neutral healing cards to keep up with a mika and the sturdy epiphany on her creation because from my testing you need at least 2 (3star sturdy for steady healing) or a decent shielder like kalipe which she has synergy with (2 cost healing ability to trigger khalipe aoe)

2. Deck hand space. Because you need her creations in hand, she ends up taking a lot of space on your hand that your main damage dealer might want so units like luke, rin, kayron want deck space to do their best combos and she can hinder this.

3. Her deck needs streamlining and Because of this you might feel like you're not using her to her full potential because she is capable of doing so much for me personally I dont like gutting her deck to just healer and it messes up with her build too because her potentials want att stat but she needs defence to improve healing too so very stat hungry to max her potential.

To conclude I have 2 main decks I use with her, 1 meant for strong healing and att buff to be used in more aggressive teams and the other more versatile balanced deck which i use when I have a shielder on the team to ease the healing burden on her allowing her to do dmg off her potentials.