At what point in The Scarlet Letter does Pearl undergo a change and why?

undergoes a change
when she perceives the difference wrought in her mother afterhas taken down her hair and removed
the scarlet "A." Hester has been speaking with the Reverendin the forest, and when
Pearl returns, Pearl's demeanor changes because "since [she had] rambled from her
[mother's] side, another inmate had been admitted within the circle of the mother's feelings,
and so modified the aspect of them all" and "Pearl, the returning wanderer, could not
find her wonted place, and hardly knew where she was." Seeing her mother so close to
another personwhen it has always been only Pearl and Hester against the worldshook Pearl to her
core. On top of this, she's only ever known her mother to wear her hair hidden under the cap and
to wear the scarlet letter; now, with her hair down and the letter gone, Pearl finds her mother
to be frightening and foreign.  

As a result, Pearl will not approach her
mother and remains on the other side of the brook. She will not...