I've had this happen and had both good luck and bad luck with the moms.
Sometimes they go on to deliver normal litters after wards and sometimes they don't, it's your call whether to breed her again.
If she has issues the next time then it's time to find a large snake

Usually when they deliver slowly over a few days and drop dead babies they recover and go on with life, it's when they breech birth that I've lost them, several times