6 day old only taking one side at a time?

HopeNotLost

I'm not sure if this is ok or not, so I am asking for your advice.

My DD is 6 days old. She eats about every 2-3 hours, sometimes she will snack in between, maybe for a couple of minutes, before falling back asleep.  She normally eats off one side at a time.  Sometimes it takes her 10 minutes and she is completely full (or so it seems) and isn't hungry until her next nursing session 3 hours later.  Other times she will eat for 45 minutes on the one side.  I hear her sucking and swallowing, so I know she is actively eating.

During the 45 minute marathon session, should I leave her at the one breast until she is done?  Or should I switch her after a certain amount of time to the other side? 

Thank you for any advice you can give me!