The fortune teller said that my wife had a bad temper after five years of marriage.

Haha, it's sheer nonsense. After marriage, it is generally said that seven years itch. There will be children after marriage, and there will always be some bad temper in life, which is normal. Don't take this to heart, or your wife will remember what the fortune teller once said if she is slightly unhappy and angry in the future. Actually, it's not. Don't affect feelings.