So Tiny/ 6 months

Hi everyone.  It is so hard to believe but Avery is now a half a year old!  Wow,  did that really fly by.  We went to her 6 month appointment yest.  She is so tiny, and I mean tiny.  She is the average size of a 3 month old.  She doesn't look that little to us, but she is.  She now weighs 12 pounds 14 ounces and is 23 7/8 inches long.  He tried really hard to at least make her 2 feet, but to no avail.  She is in the 4th percentile for both height and weight.  He is not concerned for now because she is proportional and she doesn't look malnourished.  If she falls off the chart next visit, which she may, he is going to start investigating if there is a reason.  He says it is possible that she could have a thyroid problem, but thinks it is unlikely.  For now we just need to push the feeding, as we always do.  He says she just doesn't need very many calories because she is small, that is why she is not a big eater.  She is not quite sitting up still, but is wanting to.  She is just a blast and a joy to us.