You could mention it casually next time you happen to see her and tell her the police and rspca have been informed etc...maybe she will have sense enough to cut out this disgraceful behaviour if she thinks shes been rumbled.
Or do what I did to an ex boyfriend.....cook up a pedigree chum pie, mixed up with nice gravy and carrots and peas, few herbs.....take it round as a peace offering...... see how she likes vomiting all night eh...