Please don't leave your little sister alone.(同义句)Don't leave your little sister ____ ____ ,please.

Please don't leave your little sister alone.(同义句)Don't leave your little sister ____ ____ ,please.
Please don't leave your little sister alone.(同义句)
Don't leave your little sister ____ ____ ,please.

Please don't leave your little sister alone.(同义句)Don't leave your little sister ____ ____ ,please.
Please don't leave your little sister alone.(同义句)
Don't leave your little sister （by herself） ,please.
不要不管你的小妹妹.
by oneself,独自,相当于alone.

by herself
I do it by myself.
=I do it alone.