I'm glad that the female will see a vet. I hope she gets spayed now as waiting to abort later will be more complicated and risky to her. Maybe you could give an update of how it goes. I really don't understand the whole situation
on either end. Taking bullies to the dog park, intact at that and friend bringing on in heat. I really don't believe in accidents or if they occur few and far between, most "accident" litters are very preventable. I agree that s/n would probably be the best in this case to prevent more future accidents.
On the other hand (I'm not going to flame but) I've no need to s/n my own dogs. It is my personal choice if/when I will s/n. I don't need to put my dogs through an unnecessary surgery to keep them from procreating just because a novice or less responsible owner can't keep their dogs from having accidents. I will s/n for health reasons if its in the benefit of the dog, otherwise not.
For responsible owners who chose to s/n that is great too, they've made the best decision for themselves/their dogs. So I'm not putting them down as incapable owners if they do s/n. There are irresponsible owners should s/n to keep accidents from happening but then I question their ability to own dogs responsibly period.
I will say health reasons on either side are overblown. The risk to neutered dogs and risk to intact dogs are both very small for most things. So you are just accepting of having higher (although small) risk of specific issues. I don't see one as a reason to neuter nor one as a reason to keep intact. It is all about knowing the risk and what to look out for. IMO it shouldn't be used to make the decision, just to know the risk of your decision. Hope that makes sense.