Our dad dog bred it's own pup. I didn't even know that they would, I thought they had a natural instinct not to breed it's own pup. Will this litter be ok or should we abort the babies?

I have been looking for an answer to a question all over the internet and have come up empty as of maybe now. This site seems to have all the answers so here goes nothing. We have a male and a female that are probable close to three years. Last year they had a litter in May or June that had to be delivered by emergency c-section and only one female puppy survived. We kept that stupid pup regardless, because she was kind of a miracle and all that she even lived at all. Ten months later which brings to the current date, the pup without realizing goes into heat. We walk in and find that of course dad is breeding it's own pup. I didn't even know that they would, I thought they had a natural instinct not to breed it's own pup. I guess the question is will this litter be ok or should we abort the babies? I know from previous advice from your site that I found while looking for my answer that 10 months is not recommended but what about a dad that breeds it's own pup. Please help me cause I'm not finding the answer very easy.

Thanks,
Robert