Find out what her grain ration is right now, and cut it down. 65lbs of milk a day translates to 6-8 gallons per day -- even if you put 4 newborn calves on, you'll likely lose them all with that kind of production. It's double what they need.
In your place, I'd take her down to about 6lbs of grain per day, and monitor the calves very very closely. In the beginning, esp if they've been on milk replacer, they should not get over a gallon per calf per day.
FWIW -- sometimes dairies have their herds on 30+ pounds of grain per day to get that much milk out of a Jersey. If that's the case, you need to be very careful in bringing her down to a lower amount of grain, or you'll upset her digestion and could potentially kill her.