Answer:
If the average mass of the five sisters is 52 kg, then the total mass of all five sisters is 5 * 52 = 260 kg.
If the first three sisters have masses of 43 kg, 60 kg, and 59 kg, then the total mass of these three sisters is 43 + 60 + 59 = 162 kg.
Therefore, the total mass of the remaining two sisters is 260 - 162 = 98 kg. Since there are two sisters, their average mass is 98 / 2 = 49 kg.
Thus, the average mass of the remaining two sisters is 49 kg.