OK so I am trying to figure out the name of a movie my brother and I watched when we were kids. It is a cartoon and I remember it had animals in it. One of the character's parents were killed by a poisonous gas. Then she was exposed by it and got really sick. So her friends had to go find some special flower and they had to travel all over to find it. Long story short they find it and their friend survives at the end. The name of that movie has been driving me insane and I have two other people trying to figure it out as well. Can anyone help me?

Once upon a forest

Already answered.