Feed her well for a COUPLE OF FEEDINGS then start to cut her back. This seems to lower the clutch size better and in a few months she should be shut off completely or lay much smaller clutches. You don't want to cut her back so far that she is thin and sickly. I also cut the basking temperature to just over 80F to slow her metabolism down a bit so she won't "feel" so hungry.
Good luck.
Overfed female veileds not only lay huge clutches but develop MBD usually and other health issues and often prolapse. Many suffer from follicular stasis and egg binding too.