Travelling around America/Canada on a Slovenian passport? Visa info

I have a friend from Slovenia who is travelling to New York with me (I hold an Australian passport so I’m fine).

She was wondering if it would be possible to take a short trip into Canada, and then return to the states to finish the rest of her holiday?

Would she need a multi entry visa, or are there any other option available?

Thank you.
Re-admission to the United States after Short Trip to an Adjacent Island, Canada, or Mexico? (CBP website)

I suggest going here to start:

http://slovenia.usembassy.gov/visa_waiver_program.html

I also suggest looking on Google because it saves a lot of time and often bad advice on here... plus it makes you look smarter if you can find the info yourself. ;)

That bit about readmission to the U.S. after a visit to Canada is from a quote referring to people in the U.S. under the visa waiver program, not people in the U.S. with a B-2 tourist visa. B-2 tourist visas, as far as I know are always multientry...as long as the visa is not expired, the person may enter the U.S. To be safe, it would be wise for your friend to call the visa section of the nearest American embassy or consulate and/or ask the immigration officer upon entry into the U.S. This is one of the multitude of visa questions that are not addressed on th U.S. embassy visa section website.