With a new branch of possibility now open to her, Alice dedicated her efforts to mastering it and seeing what was possible and what wasn't.
Even though she wanted to test what happens when her own blood is amplified through her body, it wasn't easy to get results.
She couldn't test if she could break out of a Personal Realm nor could she test the full effectiveness of the defences.
Alice couldn't test her fifth Sigil either since there were still some lingering after effects even though it's already been a few days since the fight with the Doctor.
She could instinctively tell that if she were to reactivate the Sigil, the likelihood of her being exiled was high.
Thus, this only left her with two Sigils that she could test out her theories with. Her third and her fourth.
The third wasn't unique by any means. It simply gave her the power to manifest and manipulate blood and metal.