Imam Hassan Askari (AS) was asked:

Why Lady Fatimah (SA) was called Zahra (SA)? Imam Ali (AS) replied: Because the heavenly feature of Fatimah (SA) used to shine three times on Imam Ali (AS); beginning of the day like sun, at noon like moon, and at sunset like a shiny star [1]. It is narrated from Lady Fatimah (SA) who said: My father prohibited me from asking anything from Imam Ali (AS) and he added: If Imam Ali (AS) brought something to the house, use it; otherwise do not ask him for anything [2]. Lady Fatimah (SA) used to say to her husband (AS): I am ashamed of God to ask you for anything that you are unable to provide [3]. Lady Fatimah Zahra (SA) used to manage her house and Ali (AS) the tasks outside the house, and lady Fatimah (SA) was happy with this arrangement as she did not wish to go out and face non-Mahrams [4].

[1] Beharul Anwaar, Vol. 37, Page 16.

[2] As Above, Page 31.

[3] As Above, Page 59.

[4] As Above,Page 81.

Source:en.shafaqna.com