If they gave her an approximation of 32wks gestation, it was based on the size of her belly alone. I have seen it said that she was told to come back for a dating ultrasound for more accuracy and she did not and that would have been a more accurate gestation. Regardless, they do have a confirmed father (via DNA) whom allegedly moved away for college in August and knows on or about when conception occurred and that timeline does align with a full term birth. They also have fetal bones, which are notoriously accurate for age dating, so there is really no doubt the baby was full term. If the defense is relying on an eating disorder causing a stillbirth, they will have an uphill battle in convincing a jury beyond a reasonable doubt, as the data from the WHO does not support this theory, where live births are not affected in starving or underdeveloped countries, nor does tacit knowledge of past decades where women were expected to remain relatively thin during pregnancy and had healthy babies. Also, only 1% of pregnancies end in stillbirth anyway, so even before prosecution presents any of the evidence they have, there is already a 99% chance the defendant is lying. Sadly, based on just the news stories since the defendant was arrested two years ago, so many stories of parents of all ages and socioeconomic status killing their own children do not make it hard to convince a jury that the defendant was responsible for what happened here.