Large black area on guppy's abdomen, varying degrees of swelling

[MyDaughtersTank]

Water parameters: 

pH - 7.4

Temp - 78F

Ammonia/Nitrites/Nitrates - 0/0/~10-20

dKH - 3-4

dGH - 8-16 (depending on water changes and when i last added a wonder shell)

 

So a week and a half ago I found one of my guppies laboring near the top of the tank with a large, lumpy, swollen abdomen and a mild prolapse.  She had been perfectly fine that morning.  I gave it overnight in the naïve hope that she was about to have fry, but the next day her scales were clearly pineconeing so I put her in the hospital tank with the meds trio and little hope for survival.  Surprisingly, over the next couple of days the swelling went way down to more or less normal and her behavior and appetite also returned to normal.  But she also developed a black area on her abdomen with some scale loss.  

She spent a week with the meds trio and minimal feeding- I did a 30% water change on day 7 and began feeding once daily.  She is still eating/swimming/pooping normally but this black spot is still a concern and now her abdomen has taken on a bit of a pointy shape.  

I included 2 pics here- the one in the breeder box is from a week ago when she was already looking better (the spot was much darker in reality than the picture shows).  The other pic with the pointy belly is from today.

Any ideas on what this is and what my plan should be from here?  Is it disease? Injury?  Infection? Parasites? Internal failures?  Should I remedicate?  Just observe?  Feed less?  Salt?

Any and all help appreciated- thank you.

 

[Colu]

 If you have done med trio I would try aquarium salt 1 table spoon for 2 gallons for 1week

[Mr_Manifesto]

If what you have been doing has been working, i'd keep doing that.  and observe.  It looks like it was some internal issue, perhaps a failed birth or injury or both?!  But if the fish looks like its improving with what you have done/did, then keeps going with that.