Breastfeeding question FTM

My baby is 1 week old today. I am told she is a poster child for latching and I have truly lucked out because she is fantastic at nursing! However, she only nurses for about 10-15 minutes on one breast each session. She falls into a deep sleep when I try to keep waking her. Could 10-15 minutes be enough? She was gaining weight at her 5 day check-in. I'm wondering if I should pump for 10 minutes to get an idea of what she is taking in but I don't want to pump too soon either.  I'd like to think this is working for us but the lactation consultant had mentioned 20-30 minute nursing sessions and we aren't there yet!