The word "SINCE" implies that something is having an effect on something so since is the answer.
There are too many pigs in the blanket to count. So many they can barley fit under the blanket.
I would say the correct answer is - she thinks that Higgins deserved it.
Here is a quote from the text to prove it:
<em>"And then you were surprised because she threw your slippers at you! I should have thrown the fire-irons at you."
</em>You can see here that she wasn't mad or surprised she did it - it was to be expected.
