Is it valid to pray the night vigil (Qiyam al-Layl) with only two rak'ahs, and is it permissible to pray Duha in an exposed workplace where men pass by?

Night vigil (Qiyam (definition) al-Layl) is a great act of worship. It is best to perform eleven rak'ahs, but it is valid to pray two rak'ahs followed by Witr, and this is considered part of Qiyam al-Layl. Duha prayer is recommended (mustahabb) but not obligatory, and there is no sin in omitting it, though it is better to perform it regularly. A woman must cover her entire body in front of non-mahram (definition) men, and her prayer is valid if men see her while she is covered. It is not permissible to use work time for anything other than work if it compromises the work, except for obligatory prayers and fixed salary payments.