Chaw Sandi Tun was arrested in October this year for her Facebook post, which compared the colour of the army chief's uniform with a longyi (sarong) worn by Aung San Suu Kyi, leader of the National League for Democracy party, rt.com reported on Monday.
"If you love mother that much, why don't you wrap mother's longyi on your head," Chaw's post read.
The political activist was sentenced under Section 66(d) of the Telecommunications Law, which bans defamation and 'disturbing' people.
According to Chaw's lawyer, she denied writing the post saying her account had been hacked.
Chaw said earlier a doctored image of Aung Suu Kyi was shared on Facebook and the wife of the country's information minister Ye Htut was one of the people who shared it.
"If they found me guilty, Ye Htut's wife is also," Chaw said in her defence.
Myanmar was ruled by a military junta since the 1962 military coup. In 2011, the military announced gradual political reforms to pave the way for a civil government.
Despite signs of freedom such as the recent general elections, Myanmar remains restricted and the military retains power.