To get back to the paper itself, I thought it was really sad how the conclusions from her paper seem to take away from what it looks like she's trying to get across through her work.
She makes extremely good statements about how important it is to support new mothers through social programs that allow them the benefit of the social standards that help their children thrive (and that she defines as the statistical construct causing previous studies to overestimate the long-term benefits in the outcomes she focused on), like longer maternity leave, access/ability to afford healthy food, less worry about financial strain, not having to work two jobs just to get by. But part of the push for these things is the idea that mothers need to be near their children for as long as possible after birth and on a social level, the availability (and acceptability) of formula as a breastfeeding substitute actually works against that, since most bosses, men, and older generations who run businesses, work in politics, and generally have a large influence on the availability of these programs are more likely to see it as "formula is an acceptable substitute, mother's are not required for the transfer of formula to infant, therefore mothers should have no problems going back to work, quickly, and with long hours". So the results of her study are more likely to have the opposite effect of what she had in mind. Breastfeeding as a social right is needed to play a big role in changing how policy makers and businesses view the role of women and their right to time off without penalty in the year following birth.