After Jason's prompting - i've created a thread for Marybeth Tinning as i did confuse her over Marie Noe.
From 1972 till 1985 she killed 8 of her own children by Munchausen Syndrome by Proxy by smoothing them.
http://www.serialkillerdatabase.net/...thtinning.html
http://en.wikipedia.org/wiki/Marybeth_Tinning
What amazes me about this case is the fact that one of the children that died was adopted yet no alarm bells were rung.