Dr. Atkins says specifically that the ketogenic portion of the LC diet should be avoided by nursing moms.

If you want to LC at this point, go directly to a Maintenance type level (which would allow for higher carbs) until you wean your daughter. So, your "LC/whole foods" plan might fit the bill...

I would imagine the introduction of ketones would make your milk unpalatable - if the resultant odors they cause in "grown-ups" are any indication. I have no idea if they would pose any danger.

When (or if) you can turn to the ketogenic portion of the LC diet, you can buy ketostix at the pharmacy - they are with the diabetic testing supplies and you might have to ask the pharmacist for them. You do not need a prescription to purchase them.