The quantity of water is 2 3/4 pints or 56 floz + 8oz tin of toms, so 64 floz, plus a kilo of veg and 8Tbs oil which I very roughly guesstimate will make up another 50 or 60 floz, for a total of about 120 floz or 8 x 15floz portions. So it seems about right. Did you possibly confuse metric and imperial measurements at some point seeing as she confusingly mixes both measurements(is my only thought)?