you can feed your snake a rodent that is approximately the same diameter as the widest point of your snake. if the rodent is a good bit smaller than the widest point on your snake feed 2
by the way this is the scale I use it cost $15 at a grocery store:
I will definitely get one of those when I get paid.
I'll keep feeding her just 1 for now and keep my hands (and my fiance's hands) out of the tank until she goes back into hiding.