You are doing fine!! A puppy can't be potty trained at 11 weeks. The time between when he feels the urge and when the 'act' comes out is a mere 10-15 seconds, if that.
ALMOST all puppy books say that. My advice is based on my recent move into my in-laws home...don't ask - long story. Find an article online that explains the bladder time frame issue, print it, highlight that section and leave with a really nice note, saying you respect her opinion and did more research on the subject of potty training and you wanted to share it with her. Tell her you feel frustrated whenever the puppy has an accident as well.
Here is a link:
Use Natural Instincts for Housetraining Puppies
It SUCKS being told how to 'parent' - and since this is a limited time situation, try and be nice, ideally, your roommate is just trying to be helpful...though I KNOW it doesn't feel that way.
Hope the time passes quickly!