My girlfriend accidentally licked a slug that crawled on her beer can at a barbeque. she's really scared. can she get sick?

Slugs and infections: Very rarely. I once bit into an apple that had worms in it. The nurse declared well we know that the apple does not have any pesticides! however, if she does develop anything it would in the GI tract and may due more to the barbecue than the slug.

Doubtful: Angiostrongylus cantonensis can be transmitted through eating slugs or snails but that is uncommon per the CDC. REf: https://www.cdc.gov/parasites/angiostrongylus/gen_info/faqs.html