Jewish law exempts from fasting anyone whose health might be even a little harmed by it - this would include pregnant and nursing women whose health (or the health of her baby or fetus) might suffer from fasting. There may be ways of eating and drinking small increments that are still compatible with fasting. However, a local competent Orthodox rabbinic authority should be consulted so that the method and amounts of eating and drinking will be done within the correct guidelines.
I did not fast last year. This year, I am nursing less, but I'm not planning to fast. I'll will try to get my eating to a minimum - a light b-fast and lunch and drink plenty of water.
Re: Any (somewhat) Observant Jews here?
https://kellymom.com/nutrition/mom/fasting.html
Jewish law exempts from fasting anyone whose health might be even a little harmed by it - this would include pregnant and nursing women whose health (or the health of her baby or fetus) might suffer from fasting. There may be ways of eating and drinking small increments that are still compatible with fasting. However, a local competent Orthodox rabbinic authority should be consulted so that the method and amounts of eating and drinking will be done within the correct guidelines.