I don't think you are "too thin" to nurse unless you stop producing milk.
20+ years ago, in the early coverage of the famine in Ethiopia (which sparked Live Aid) Time magazine had a cover pic of an emaciated woman and her infant son. The picture sparked a minor controvesy with people claiming that they were faking the news, since the child looked fairly healthy and the woman, though alarmingly thin had large full breasts. They had to run a story with medical experts explaining that even under starvation conditions a mother produces milk for her child.
The point of that ramble of course is that if a literally starving-to-death woman in Ethiopia can nurse her child a skinny Westerner will be fine.
20+ years ago, in the early coverage of the famine in Ethiopia (which sparked Live Aid) Time magazine had a cover pic of an emaciated woman and her infant son. The picture sparked a minor controvesy with people claiming that they were faking the news, since the child looked fairly healthy and the woman, though alarmingly thin had large full breasts. They had to run a story with medical experts explaining that even under starvation conditions a mother produces milk for her child.
The point of that ramble of course is that if a literally starving-to-death woman in Ethiopia can nurse her child a skinny Westerner will be fine.







I'm 5'11, 130lbs (before I got prego with #2) and here is a picture of my DD at 9 months:



: My itty-bitty not-even-A-cup breasts never had a supply problem. I actually don't even have all the tissue on my right side as I was born without it so tell that doctor to SUCK ON THAT! 
