On the contrary, what happens with family members over time is life gradually becomes better for them as well. The levels of improvement vary upon many factors.
One can argue that naturally over time as a Satanist progresses, those in their environment tend to slightly progress as well in their lives due to the increased positive energy of the Satanist.
Two more points towards this involve the fact that a Satanist will often times perform magical workings to better their surroundings and sometimes even better the lives of their loved ones. This is done with the prosperity and protection a Satanist can bring as they evolve and follow their path towards spiritual progression.
The last note to consider is that the more a Satanist improves and works for Satan and The Gods, the more they'll receive in return as well. Blessings and protection can be given for a Satanist who truly dedicates themselves and does what they can to improve their own lives and the lives of others.
This person needs to not be afraid of such bad things happening.