Mash on at 5.50pm 9.28am 57.5g in Off the boil at 10.30
Based on boiling 24.00 gallonsliters at 1.050 for 60 minutes, this will decrease your wort by 3.00 gallonsliters, bringing your after boil OG to 1.056. You wanted an OG of 1.051. It looks like it will be over.