Only eats on one side.

My LO will be 4 months the 19th and since day one she would only eat one side at a time. She goes anywhere between 2-3 hours between feedings during the day. She only eats for about 10 mins and then is full. She is growing at a normal pace. She is 12.5lbs (weighed her this morning holding her) she was 6lbs 8oz at birth. So I guess my question here is: does anyone elses little one eat for short periods of time only on one side each feeding