A good vet will see a critter on emergency basis. It costs more.
Don't feed her asprin.
You've been adopted. ;) Suck it up and get 'er done.
/johnny
Seconded — the most important thing is that she is using the litter box.
Get her to the vet for a good once-over when you get a chance. But you may find that she, as with many cats, just doesn’t like to be touched in certain places. One of my cats loves attention but will go psycho if you try to touch his feet.