Four days on she appears to have acquired 4 extras!!!!
DS1 thinks it's hilarious - "imagine if a human with triplets grew an extra boob!"
(I think logically there must have been rudimentary ones there all the time, hidden by the fur, and the demand has developed them - but it does look funny, they're right up by her armpits, the others are at the bottom of her belly, there's a gap in between )