Years before Lacey Spears poisoned her own son, three children became sick while under the mommy blogger's care, a new book claims.

In the bombshell release, My Sweet Angel, author John Glatt alleged that after digging deep into the 27-year-old's past, he discovered that three kids had developed serious ear infections after being under Spears' watch.

Her son, Garnett, also suffered an infection at the time, Glatt claimed.