She fasted to make up days from Ramadaan without her husband’s permission
Question

A woman made up fasting two days she missed of Ramadaan without her husband permission (she did not tell him). She felt shy to tell her husband. If it was not permissible for her to do this, should she expiate?.
Praise be to Allah.A woman has to make up the days that she did not fast in Ramadaan even if that is without her husband’s knowledge, and when it comes to an obligatory fast, her husband’s permission is not essential. So the fast of the woman mentioned is valid. As for non-obligatory fasts, a woman should not fast when her husband is present except with his permission, because the Prophet (peace and blessings of Allah be upon him) forbade women to fast when their husbands are present without their permission, apart from Ramadaan. 
And Allah is the Source of strength. May Allah send blessings and peace upon our Prophet Muhammad and his family and companions.