Is it normal to have a vaginal odour after childbirth?

It is generally abnormal. Normally, tissue such as endometrium mixed with blood is expelled through the vagina after delivery and may have a bloody odour but no foul smell.
If the necrotic tissue in the uterus is not discharged in time or if poor postpartum hygiene predisposes to diseases such as uterine infection or vaginitis, vaginal odour can occur and further definitive diagnosis and prompt treatment is required.