There is no good reason to do a spider x spider pairing. Why anyone would do a pairing that would produce guaranteed failures is beyond me when there are endless options. Just because you personally don't have another female available doesn't mean you should cut your losses and just do it anyway for the few that will survive. That would be considered very irresponsible breeding. You have plenty of other options. You could wait a year or you could choose from the many breeding ready females for sale right now if you need to breed right now. There is no excuse for pairing two snakes that will produce known failures.