Your in a bit of a predicament here....
You have rights to fight the electricity bill and would win out legally with that no problem. But the catch is you would probably lose your appartment in the process...
If it's an illegal appartment, there is no valid "lease" and therefore at best would be considered on a month to month basis and you could have as little as 30 days to vacate the premises.
If you were in a legal and binding lease all you would need to do is ask for her to produce the electricity bills to prove that the consumption has risen since you moved in and since you got your animals.
In this situation, I would keep my mouth shut, pay the darn 30$ a month (I wouldn't give her any lists of animals or equipment) and start looking for another place.
Keeper of 5 snakes, leopard geckos, 1 green iguana, 20+ tarantulas, 2 dogs & a bunch of rats!