Is the sister who posts pictures of her deceased parents on WhatsApp committing a sin?

It is better not to place pictures of parents because photographic imaging of living beings is a matter of dispute among scholars, as is keeping pictures for memory. There is no difference between the living and the dead in this regard. We do not judge it sinful due to the existence of disagreement, but it is advisable not to place the pictures and to suffice with placing pictures of non-living beings.