YOU SAID:

she sells sea shells on the sea shore but the sea shells she sells are the ones she stole

INTO JAPANESE

彼女は海岸で貝殻を売っているが、彼女が売っている貝殻は彼女が盗んだものだ

BACK INTO ENGLISH

She sells shells on the beach, but the shells she sells are stolen by her.

INTO JAPANESE

彼女はビーチで貝殻を売っていますが、彼女が売っている貝殻は彼女に盗まれています。

BACK INTO ENGLISH

She sells shells on the beach, but the shells she sells are stolen by her.