There is no way in hell she would have had streptococcus be the cause of her amputation. streptococcus would be a local infection via a wound somewhere, and would affect that region and nearby flesh only.
The chances of her getting infected on all 4 limbs at the same time is nill.
What probably happened is this:
She got streptococcus via vaginal tearing or other method (pregnant women have lowered immune system) this led tot toxic shock syndrome.
In order to treat the shock the hospital likely used epinephrine..if too much epinephrine is given (can easily happen, its hard to estimate the correct amount to counteract shock) then it would have caused the veins and arteries in her extremities to fuck up, collapse etc which would have necessitated the amputation.
So although the streptococcus was the first domino, it seems a miscalculation of epinephrine on the Hospital’s part is what directly led to the amputation. In which case she would have good cause for a malpractice lawsuit.