Is it permissible for an elderly widow to leave her home during the waiting period (iddah) to attend a women's banquet or to obtain necessary official documents?

The waiting period ('iddah) for a woman whose husband has died is four months and ten days, unless she is pregnant, in which case her 'iddah ends upon delivery. During this period, she must observe mourning (ihdad), and this is obligatory for both the old and the young. A woman in 'iddah is permitted to go out during the day for a need or necessity, and there is no harm in it if she is veiled and has not adorned herself or used perfume. She is also permitted to go out at night for a need or for companionship, provided that she returns and spends the night in her home.