Answer:
7/8 cups
Step-by-step explanation:
This is just a matter of converting fractions. First, you'll make 1 1/4 = 5/4, then multiply by 2 to get 10/8. She has 3/8 cups already, so you'll subtract to have a remainder of 7/8 cups needed from the second bottle.
Draw your number line from 1/8 to 16/8, and put a dot on 3/8, 10/8, and 7/8.