Hm, I was a very sceptic that she had secret fill-up. Now I checked all her tweets.
Now I believe since December 2011 she is doing fill-up every 3 months - if she isn't a marketing pro only:
February 15, 2011: BESHINE is getting bigger boobs today!
Then it started:
December 9, 2011: two support bras on and now off the the gym.. my boobs feel heavy today.
March 12, 2012: wow.. my boobs are so heavy today, love that feeling

June 16, 2012: my boobs feel extra heavy today...
September 5, 2012: the boobie greed monster is getting bigger and bigger… i think you know what that means

December 10, 2012: feeling so augmented today

(this could reference to her booty augementation, only)
March 5, 2013: the bigger my breasts get, the more sensitive my nipples are