DH was not raised around little kids and knew very little about them, while I had tons in my family. We'd been married a short time when he came home from work and asked out of the blue how long you should breastfeed a baby. I said doctors were going back and forth on it (because they were at the time) but that a year seemed a good amount of time, and jokingly replied that my personal belief was that I'd stop as soon as the kid bit me pretty hard. I asked why he was even bringing it up and he said he was working with a guy whose wife was still breastfeeding their kid at almost FIVE. We were treated to that visual at a company party not too much later, so I was happy for the warning. Boy, did she know how to clear a space.
I'll be the wet blanket here. If there are worries that the child will be embarrassed by the photos when they are older, then the child is too old to be breastfed. By 3, 4, and 5, this is almost never about nutrition. I don't even think it's usually about the child's need to bond. I think it's usually about the mother's need.