5 gallons mash water, 2 gallons sparge water. Had higher efficiency, (85%) so boiled less and took refractometer readings until OG was 1.052
Based on boiling 6.50 gallonsliters at 1.048 for 35 minutes, this will decrease your wort by 0.58 gallonsliters, bringing your after boil OG to 1.052. You were planning on an OG of 1.052 so you are right on track. Nice job!