Am I Required to sit Shiva after the passing of a Non‑Frum Sibling?

Question

Am I obligated to observe mourning practices for a non‑religious relative? A sibling of mine passed away. We were not close, and they lived a completely secular lifestyle. Am I halachically obligated to observe the formal laws of mourning, such as shiva and aveilut, following their death?

Answer

From a strict halachic perspective (mi‑din), you are not obligated to observe the full laws of aveilut—such as sitting shiva or refraining from work and regular activities—after the passing of a non-Frum relative. This applies even if the individual is technically classified as a Tinok Shenishba. Nevertheless, common custom (minhag) is more flexible. Many people do observe Shiva and Shloshim even in such circumstances, particularly out of respect for family, communal expectations, or personal emotional needs.

Practically speaking, this matter is largely left to your personal judgment. You may consult with a rav if you feel conflicted or unsure. You are permitted to be selective: you may choose to observe certain aspects of mourning while being lenient with others. For example, one may attend Shul or work, or leave the house, while still marking the loss in quieter, more personal ways.

However, with regard to the first day of Shiva which is the day of the burial, since some Poskim require its observance by a Tinok Shenishba, therefore it is proper to follow all Shiva laws throughout the first day.

In summary:

While you are not halachically required to keep full shiva or aveilut in this case, it is entirely acceptable—and often appropriate—to observe Shiva and Shloshim, particularly on the first day, which may be obligatory.

Sources:

See https://shulchanaruchharav.com/halacha/7-mourning-the-passing-of-non-religious-relatives/