Hello
Thanks for posting your query at DoctorSpring.com
I can understand your concern.
You could have transmitted the virus to her, though you got the blister after 36 hours, you still have a history of recurrence of the cold sores, which could have led to the transmission.
Ideally the transmission is highest in presence of blisters, but there is viral shedding in absence of blisters also.
You probably got the blister because of the friction in the area and re activation of the virus.
Even though she might be having hsv 1 virus already, she could still get lesions. But it's unpredictable, her immune system may even fight the virus and she may not get any manifestations.
Please let me know if you have any queries.
Take care,
Regards.