Travelling on I-551 (US to Canada by road)

[leon_nerd]

Hi,

I am not sure if this is the right section but will post anyways.

My brother-in-law is a US Citizen. His spouse recently got into US on CR1 Spouse Visa. The VISA has the I-551 mentioned at the bottom. She has to travel to Canada by road. Is she authorized to travel to Canada? Also, does she require anything else to enter back into USA?

Thanks.