"I took a closer look at her and also noticed, that her genital
area seems a bit swollen and very pinkish "
Wow--that sounds like an infection (I'm just trying to think of what I would
be thinking if one of my postpartum patients looked like that). Can you
tell if the area is warm and tender, too (other signs/symptoms of
infection)? If it is dark pinkish and not dark purplish, I wouldn't suspect
a hematoma, which is another possibility...
If infection, act fast (sounds like you are). The area is very vascular and
open to the general circulation because of the births so septicemia
(generalized infection--life-threatening) sets in rapidly. This may be
beyond the scope of oral antibiotics--consult a vet.
Whit