She was aware that stopping her would make Audrey more disappointed in her but she also didn't want to see him hurt in any way.
And that is why she was in a dilemma.
Should she stop her best friend even at the expense of making her angrier or should she watch the man she loves so dearly get severely hurt by her best friend?
Joanna knew that no matter what choice she made, one out of the two people she loved so much would end up getting hurt.
As Audrey drew closer to where Amos stood Joanna became even more confused.
She didn't make up her mind until Audrey revealed her clasped fist and tried to punch Amos in the chest.
The instant Audrey launched her secret attack which was aiming at Amos' right chest, Joanna ran in between them with her hands spread.
Had Audrey not withdrawn her punch at the last minute, she would have punched Joanna in the chest.