Runa Khan, from Luton in southeast England, admitted four charges of disseminating terrorist publications between July and September 2013 after sending Facebook posts containing a picture of a suicide vest with the words "sacrifice your life to be in Islam".
She also described how fighters could gain entry into Syria, adding: "Sisters, if you love your sons, husbands and brothers, prove it by sending them to fight for Allah.
"Don't you want them to prepare for you a palace in Jannah."
The jury at Kingston Crown Court in southwest London also heard that the 35-year-old had a photo on her mobile phone of her two-year-old son with a toy rifle and a jihadist book.
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They heard that she had praised an article on how to prepare young children for jihad.
"Don't underestimate the lasting effects of what those little ears take in during the first few years of life!" said the article. "No child is ever too young to be started off on jihad training in one form or another."
Judge Peter Birts said a custodial sentence was inevitable given the "utmost gravitas" of the charges.
Commander Richard Walton, Head of the Metropolitan Police's Counter Terrorism Command said: "This is a case of social media being used as a tool for terrorism. Khan used it to spread extremism, radicalise others and justify children being used for terrorism.