How long would you wait to get your child tested?

***This is by no means judgment. Just curious what others would do in comparison to myself. No one is wrong or right, it’s your child, your the parent, your decision. ***

A family friend has a child who is 2 years 4 months old. She is off the charts for her growth. It’s so behind she fits into 3-6 month size clothing. His mother dates my father so I hear about this child all the time and how she’s so cute and tiny. My 16 month old is literally twice her size and he’s only in the 15th percentile so he’s on the smaller side but his doctor is not concerned at all. Her doctor is concerned and wants to refer to a genetic specialist for further testing and has wanted to do this since she was 6 months old. Her parents are refusing to do any further tests saying they are petite people and she is just following in their footsteps. It’s 100% their right to decide for their child, but it did ignite some thinking in my end on what I would do in that situation.

I am very analytical. I want to know ALL the information so I can analyze my situation, my options, learn as much as I can, then decide how to move forward. The very first time there was an indication of an issue I would want every test.

What do you all think? How long would you wait for testing? I’d love to hear from everyone but particularly parents who have experienced having to make the decision. What did you do and what was the outcome?