Joni earned $0.625 per day for two days as interest on her $1,000.00 investment. What percent interest did she earn in total? Give your answer to three decimal places.

Joni earned $0.625 x 2 = $<<0.625*2=1.25>>1.25 interest in total.

Her percent interest is $1.25 / $1000 x 100% = 0.125%.
Thus, Joni earned 0.125%. Answer: \boxed{0.125}.