An empty (olympic) bar is usually 20kg, or 20.4kg/45lbs if you live in poundland. Difficult to lift a lower weight than that if you go the barbell route.

Most girls at my gym lift more than just the empty bar for reps, even if they look new to the movement, so 17kg sounds like an underestimation for 1rm. When I first introduced my sister to the movement, she did 3x12 of an empty bar just fine.