A.V.
No. People who are literally starving in Africa can still feed their child by breastfeeding.
I went back to work, nursed and pumped, ate too many frozen dinners for lunch and my DD is fine. I know it's not always easy, but a convenience diet is not, IMO, a reason to go to formula. If a woman is truly worried about her child's milk, she should worry about herself.
Besides which, I'm sure you noticed that formula is expensive. If someone is watching her budget, she can knock two birds at once by taking care of herself and thereby taking care of her nursling by proxy.