Ditto to what Glenda said!!! This pregnancy should be terminated ASAP.
If you decide to continue the pregnancy, get her to the vet for a C-section the second she goes into labor (or earlier if the vet advises it). Early labor is likely with such a big father, so the survival of the pups is very questionable no matter what you do. The average gestation is 63 days from the date of ovulation.
Mismating and Pregnancy Termination (last article)
http://www.lowchensaustralia.com/breeding/lostpregnancy.htm
The mismate shot is evidently out of favor due to the increased risk of pyometra. Prostaglandin F2alpha can be used if a pregnancy is confirmed 30 days after mating. The treatment takes 4 days.
http://www.peteducation.com/article.cfm?cls=2&cat=1628&articleid=930
Several changes that may be noticeable in the bitch the last week before delivery include a distended, 'dropped' abdomen, enlarged and softened vulva, enlarged nipples, and full mammary glands. Taking her temperature at least twice a day the last 10 days before the delivery date is also helpful. Some bitch's temperatures will drop below 99°F within 24 hours of delivery. This may not be seen in all bitches, but is another indicator. Loss of appetite and nervousness (pacing, panting) alternating with sleep also indicate the time is near.