Public Breastfeeding

Everyday for the past year and half I venture out into public with my toddler who still nurses, quite frequently. Inevitably, she will decided it's time to nurse at the most inopportune times. For instance, this evening, while my eldest daughter was at dance class, my toddler and I went to the library. I was browsing for books to aid in my current research project while muttering useless information to my tiny tot about the Dewy Decimal system. After about a quarter of an hour of this she blurted out, quite loudly, "Bitty! Bitty!" (Which was taught to her by my husband since we started watching Little Britain.) We found a quite place in the Children's section of the library, which is typically the safest place to breastfeed because its usually just parents and children. Now, everyday I dress with breastfeeding in mind, I try to be as discreet as possible. I wear a nursing tank underneath a shirt that easily lifts up, this way no tummy or cleavage is visible. Anyway, we took a seat and nursing promptly commenced.
Small children always seemed genuinely fascinated by breastfeeding. I can always tell which children have little to no exposure to breastfeeding because they seem to be the most intrigued. Today, this adorable little boy, about five or so, took a seat next to me and shyly asked "Whacha doing with your baby?"
"I'm feeding her."
"You have a bottle in your shirt?" he asked as he was peering over the baby's head.
"Nope, I'm breastfeeding her." I thought I should leave the explanation of this beautiful act to his parent, I didn't want to cross any proverbial lines.
The little boy sat next to me for another five minutes or so showing me a book about colors. Finally, his mother came looking for him. The first thing I noticed about this woman was the look of horror on her face when she saw me. I told her she had a very sweet and inquisitive boy with great manners. This woman was furious, she didn't return my smile and very stern looking. She sent her boy away and quietly asked me to go to washroom to finish nursing my child. Hmmmm, I could go crazy lactivist on her or be polite.
I said this "Don't you want you son to know that this is normal? Thanks for your suggestion, but have you seen the state of the bathrooms here? I'd no sooner eat in there, why should she? I'm sorry to offend, but I am going to pass on going to nurse in the bathroom."
She left in a hurry and fetched a librarian, apparently she had told him a lady was exposing her private parts in the Children's section. The Librarian seemed a relieved to see that I was breastfeeding. He told me that I could stay there, nursing, as long as I needed. I childishly wanted to say to the lady "Take that!", but I didn't think it would be appropriate.