她也不知道自己怎么又突然想到这两个女人，应该是以前留下的阴影太大了吧。

她也不知道自己怎么又突然想到这两个女人，应该是以前留下的阴影太大了吧。

Results (English) 1:

She didn't know why she suddenly thought of these two women, it should be because the shadows left by them were too big.

Results (English) 2:

She didn't know how she suddenly thought of these two women. It should be that the shadow she had left before was too big.

Results (English) 3:

She doesn't know how she suddenly thought of these two women. It must be that the shadow she left before is too big.