The temperament issues are there when she has a Scorpio person. It is the sign of Mars and Mars is aggression. I strongly feel by what you say that her Ascendant is Scorpio and not Sagittarius.
Moon is very weak in her horoscope as it is posited in the 8th house. Saturn in transit is in the lagan, which brings depression and fear. That is why I want her to do the remedies which I have provided. She should wear a good Pearl in Silver as a Moti or a ring on her right hand ring finger. It will take her out of depression and negative thinking.
If she is wearing Yellow Sapphire she can continue wearing it. It does not have any harmful effect as per her horoscope.