If she has a Small Skeletal Frame, her weight should be: 138 lbs to 151lbs.
Other weights for 6 ft women are:
Medium Frame: 148 lbs - 162 lbs
Large Frame : 158 lbs - 179 lbs
Weight for 6ft men are:
Small Frame : 162 lbs -179 lbs
Medium Frame: 171 lbs -187 lbs
Large Frame: 181 lbs - 207 lbs
Weight for 6'1 women are:
Small Frame: 141 lbs to 154 lbs
Medium Frame: 151 lbs to 165 lbs
Large Frame: 161 lbs to 182 lbs
Weight for 6'1 men are:
Small Frame: 165 lbs to 179 lbs
Medium Frame: 174 lbs to 190 lbs
Large Frame: 184 lbs to 210 lb
My height: 184.5 cm (6&1/2 ft)