From the break of dawn, it is forbidden to eat or drink before praying. The Sages support their words (Berakhot 10b) on the verse (Vayikra 19:26), “Do not eat upon the blood,” which they interpret
However, one may drink water before praying because there is no element of pride in drinking it. Similarly, one may eat food and drink beverages that are medicinal, as there is no element of pride in taking medicine (SA 89:4). For example, someone who is suffering from constipation may eat prunes before prayer, since she is eating them as medicine (see MB 89:24).
A woman who is so hungry that she cannot concentrate on her prayer may eat before praying, because she is considered like a sick person who must eat; her eating does not contain any element of pride (SA 89:4; and see MB 26).
It is proper that women who generally fulfill the obligation of prayer with the recitation of Birkhot Ha-shaĥar and Birkhot Ha-Torah (as explained above, 2:4) be strict not to eat or drink before saying those berakhot, in addition to reciting them as soon as possible after they wake up.