Shabbat/Jewish Festivals with a Non-Observant Jewish Parent

You should spend Shabbat or Jewish festivals with your non-religious Jewish parent (even in a non-religious environment) if he or she wants you to, as long as you can still observe all of the Shabbat or Jewish festival laws AND if your parent needs your help. 
Note You do not need to stay with your parent if your parent does not need your help or if you will not be able to fulfill all of the requirements of Shabbat or the Jewish festival.