All perfect praise be to Allah, The Lord of The Worlds; and May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
When a person starts an obligatory prayer, it is prohibited to interrupt it unless there is a necessity, such as protecting his life or wealth, and so on. Allah, The Exalted, said(what means), " and make not vain your deeds!"{Muhammad/33}.
Therefore, it impermissible for a wife to interrupt her prayer upon the arrival of her husband because there is no evidence in Sharia that obligates her to do so. It is imperative that a Muslim realizes that prayer is a pillar of Islam and one of the key acts of worship that brings him/her nearer to Allah, The Almighty.
Therefore, he/she must perform it with humble submissiveness, and not to interrupt it, save for a necessity. And Allah knows best.