dana perino and bush were visiting families at the walter reed military hospital in washington , d.c. in 2005 .
perino said one mother of a soldier from the carribean was devastated .
` she yelled at the president , wanting to know why it was her child and not his who lay in the hospital bed , ' perino wrote .
perino said bush ` needed to hear the anguish ' and later said he did n't ` blame the woman one bit ' for being mad at him .
perino shared the story in her new book and the good news is : lessons and advice from the bright side .