Please read the thread I started on the subject for my views and opinion, can't be arsed to repeat myself.
General overview of my opinion:
Rear brake SS ok
Fixed brakeless ok (assuming you can control it properly)
Front brake SS just plain retarded for the reasons stated in my thread.
hmmmm. i think you're missing the point... it's can be OK but in general it is not, 90% of the time it is definetly not ok, but in rare occasions certain riders on certain bikes in certain towns can get away with it BUT leeds is not like flat london and she isn't riding by herself safely but in a pack with fast riders through traffic with some brakeless (experienced and in control) riders and others with front brakes or even 2 - she needs the backup of another brake if she is going to continue riding singlespeed and not fixed.
hmmmm. i think you're missing the point... it's can be OK but in general it is not, 90% of the time it is definetly not ok, but in rare occasions certain riders on certain bikes in certain towns can get away with it BUT leeds is not like flat london and she isn't riding by herself safely but in a pack with fast riders through traffic with some brakeless (experienced and in control) riders and others with front brakes or even 2 - she needs the backup of another brake if she is going to continue riding singlespeed and not fixed.