I breast-fed both my daughters, but I would challenge anyone to notice that they saw anything objectional - and this was 40 years ago! I was careful, of course, and on the rare occasions that we ate out we always sought-out a quiet, out-of-the-way table. No problem. Never been to a Nandos so don't know the layout, but it surely is possible to be discreet today? She should not have been abused.
Rather agree with NJ re. spoon-fed toddlers, ghastly sight and put me off my meal - a special area is really required there.