Um, first off, it doesn't say "in the middle of", it just says in the clothing department. That's about 1/3 of the store layout right there, so that could be anywhere by a dressing room, which usually has a bench near and is blocked from main traffic view, but would have Target employees nearby.
Second, our nation is really a bunch of pussies on this subject. Love of god, it's a breast, the overwhelming majority of us have had one in our mouth at some point in life, whether for sustenance or fun. What's the fallout from this act? She wasn't having sex in public, she was feeding her baby, and yes, I freely admit I would've have gone several shades of scarlet had I seen, but that's on me, not her.