1)If Rahu in 4th house then his mother may be sick or suffering from health problems.
2)If Rahu in Capricorn Sign in 4th house and Rahu Mahadasha is started then death of mother may be possible during Mahadasha of Rahu and Antardasha of Rahu.
3) If Rahu in Aries, Gemini, Cancer and Virgo sign in 4th house then Native may gets all sorts of Materialistic happiness.
