YOU SAID:
She will coming around the mountain when she comes
INTO JAPANESE
彼女が来ると彼女は山を回ってくるでしょう
BACK INTO ENGLISH
She will come around the mountain when she comes
INTO JAPANESE
彼女が来るとき、彼女は山の周りに来るでしょう
BACK INTO ENGLISH
She will come around the mountain when she comes
That didn't even make that much sense in English.