Summoning Abigail drains Sanity by 50 points. When she "dies", she will drop the flower so Wendy can spawn her again after the cooldown period has expired. Note that one hit from the player will kill her and she can often be targeted unexpectedly by the player during battle.

What happens if you attack Abigail?

You can revert her back into a flower by hitting her. If you manually hit Abigail, she will instantly die and her flower will be dropped on the ground.

Why does Wendy's sanity go down?

Wendy's attacks are 25% weaker than most other Characters' in order to balance out the ability to summon Abigail and the lowered sanity drain. when Abigail is destroyed by an enemy and her power level is reset.