Was she typical or exceptional?

I believe that Townsend would argue that the life of Malintzin was typical to the time and the region.  She was the child of a concubine wife not the head of the house.  So even though she may have been in a noble family she was sold as a slave.  This wasn't rare for the region that she lived due to the subordinate relationship her village had related to the Aztec empire.  While she was in possession of the Spanish was given as a gift for assumed advantage of Cortez. Townsend would argue that this was a common practice of the time and a typical interaction for the Conquistadors to give natives to their comrades as prizes. 
I think though that Townsend would state that even though her life path was typical, the way that she used her opportunities and her talents made her exceptional.  Even though she was a slave and given away as a gift after her experience translating for Cortez she was able to marry a man that gave her relative high status.  Her marriage to Jamarillo was at the time the gave the highest amount of advantages.  Another testament to her being exceptional is the testimony form the court case between her daughter Dona Maria and her husbands second wife Dona Beateriz.  During that trial the defendants brought witnesses to disprove Malintzins importance which non of them even 30 years later were willing to do.  This showcases her extraordinary abilities because at the time period their were plenty of translators but she was the one to make the most impact and be chosen to directly work with the Cortez.