Bnuuy

It was intentional misspelled, whenever someone sees her or any rabbit character I think, they mostly say bnuuy instead of bunny

Oh wow, you figured it out on your own? So impressive *claps sarcastically*. Next time, don't ask me stuff you already freaking know the answer to, genius. (¬_¬)
But, yes, you're right. It's a cute way of saying bunny. Whatever. (~_~;)