Are woman required to daven the same as men or once a day is enough?
Yes, women are required to daven 3x a day, Shachrit, Mincha, & Maariv.
There are specific scenarios though, that a women is exempt from Maariv such as if a women already got into bed for the night she would not be required to get out of bed and get dressed to pray. A man though, is required to get out of bed and get dressed to daven Maariv even though he was already in bed.
The concept is that men have Maariv as a “chiyuv” but not women. For women Maariv is still only a Reshus. However, contrary to popular assumptions, Reshus is still a requirement except in certain circumstances. Reshus does not mean “optional.”
For shachris Women are only required to say ברכות השחר ותפילת י"ח. If possible, women should also say ברוך שאמר ואשרי וישתבח.
By Mincha and Maariv women are only required to say Shmonei Esreh.
Women just like men are required to daven shachris before the zman tefilah.
Women just like men are not permitted to eat before davening shachris. Drinking water or coffee before davening is permitted for both men and women.
Rabbi Yitzchak Abadi in the second volume of his Ohr Yitzchak discusses this topic at length and enumerates the many benefits of tefilah and its importance. אור יצחק ח’'ב http://hebrewbooks.org/pdfpager.aspx?req=54963&st=&pgnum=26