Need advice...

Gwen • Had my sweet rainbow baby girl on April 3, 2017! 👶🏻🚼🍼 So incredibly blessed. ❤️
I had my 20 week scan today (I will be 20 weeks tomorrow) and they said the baby was measuring a little small. They said they wanted her weighing closer to a pound and she's weighing 9 ounces. Which according to this app she should roughly be only 8.5 ounces at this time. They scheduled another ultrasound for 24 weeks and said if the baby doesn't grow like they want her to that we will have to go to a specialist. Dr said at this point it's looking like we will have to go to one. What can I do to make her put on weight? I'm eating until I'm full. I did start drinking almond milk today to get more calcium in my diet since I'm lactose intolerant and won't drink milk. But everything else looked good for the baby. She was active and her heart rate was 142 today! They said she could just be a small baby or have chromosomal issues but I'm only 4'11 and my husband is 5'8 so we are both smaller than average person.... I'm honestly thinking she's just going to be small like her momma.