I saw that there are many blogs about this... I really read only two... :D
Anyway after I have read the Big Mam article on the wikia - thx for this - as it seems I can't figure what happens just by reading myself, I came with my own theory. I hope.
My opinion is that Big Mam must have a bugs related DF.
1. The name. Big Mam may refer as a queen of the bugs.
2. Acid flowing out of her mouth.
3. Her obsession with sweets.
4. (I had another one but I forgot it while I was writing these 3)
5. Her polka-dotted dress resembles some bugs' patterns.
Also I think this could be a first case of DF taking control over user. As in creating withdrawal symptoms.