Can women read Fajr Salah before the jamaat time?
In the name of Allah, the most Beneficent, the most Merciful.
In the last part of the night when it is nearing dawn and in the east where the sun rises some whiteness is visible in the length of the sky. After sometime it appears at the corner of the sky in its breadth and spreads quickly and very soon it lights up everywhere. So from the moment this whiteness appears the time of Fajr prayer will begin and it lasts till the rising of the sun. (Raddul Muhtar p.14 v.2)
As soon as the Fajr prayer starts it will be permissible for women to read salah. They do not have to wait until the Jamaat time. In fact it is actually preferable that women offer their Fajr prayer when it is still dark. (Beshti Zewar P.84)
Therefore, in regards to your question as soon as the Fajr prayer starts (4.27am) it will be permissible to read the prayer.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham.