The very fact your friend has lochia
which has an offending smell indicates that she is having infection of the uterus
. If may be or may not be due to some retained products inside the uterine cavity
which can be ascertained by ultrasonography
Anyway, she is having puerperal sepsis
and hence she needs an antibiotics treatment.
Moreover, her legs are swollen. This can happen after delivery due to formation of clots in the deep veins of the legs. This is a rather serious complication. These clots can get dislodged and block the vessels of vital organs like heart, lungs, brain, etc.
Having oversized belly immediately after delivery is normal and needs exercises to get it to normal size and shape.
Please insist on her reporting to her Obstetrician ASAP and get admitted to the hospital till she gets cured.
I hope this gives you the required message.
Dr. Nishikant Shrotri