At what age does breastfeeding become inappropriate?

Australian belly dancer Al Musa (age 51), has told the Daily Mail that she will allow her five-year-old daughter to continue feeding until she asks to stop.

Currently the mother of three willingly breastfeeds her daughter wherever and whenever she asks. “Aminah took to breastfeeding easily and the moment I felt that bond, I was instantly hooked,” she says.

Maha’s two sons aged 16 and 13 were weaned off breastfeeding when they turned two, but Maha says her daughter can breastfeed until the age of 10, if that’s what she wants.

“I believe it helps boost her immune system. To this day, she is very rarely ill and her temperament is calmer and more relaxed than the other children,” she says.

Do you think that five is too old to be breastfeeding? At what age do you think it becomes inappropriate?