If she is malnourished the baby risks being stunted, which can happen when anemia and malnutrition is combined.
[hemocue.com]
Blood tests for anemia, electrolytes, calcium, phosphorus, magnesium, ferritin, vitamin B 12, and folate should be considered for assessment of major micronutrients.
[ncbi.nlm.nih.gov]
A deficiency in this vitamin may cause pernicious anemia. This is a type of anemia caused by a decreased ability to absorb B-12 efficiently.
[healthline.com]