she ias quite a different girl__she was five years ago.

she is quite a different girl_from_she was five years ago.
使用了different from，from后(the girl)she was与五年前的她相比。

应该是as吧！！
如果是from，后面应该有个what吧！！

from what.她和五年前大不相同了。/她不再是五年前那个女孩了（有了很大变化）。

as
She is quite a different girl as she was five years ago.
=She is quite a different girl from that she was five years ago.

要填：from what

因为：she is quite a different girl from/what she was/ five years ago.划斜线部分是断句，读开来就行了。

意思是：她现在跟五年前的她是那么的不一样

填since 因为是从某个时间点