Jarir bin 'Abdul Hameed al-Razi جرير بن عبد الحميد أبو عبد الله الضبي · Fasting (Kitab Al-Siyam)

When the Prophet (ﷺ) entered upon me, he would ask: Do you have food ? When we said: No, he would say: I am fasting. Waki' added in his version: Another day when he entered upon us, we said: Messenger of Allah, some pudding (hair) has been presented to us and we have retained it for you. He said: Bring it to me. Talhah said: He fasted in the morning, but broke his fast (that day).

It is not allowable for a woman to keep (voluntary) fast when her husband is present without his permission, and she may not allow anyone to enter his house without his permission.