I need some advice. My best friend has an almost 13 month old that since about 3months old has shown some odd behaviors that I’ve noticed but I’m not sure if I’m just paranoid or if my concerns are valid. Please feel free to provide feedback...

-Around 2-3 months I noticed she constantly would arch her neck/back when being held and this continued until around 8-9 months.

-this arching seemed to delay her ability to sit up, she will sit up now at 12 months but rarely and instead will roll to her stomach and crawl instead of ever sit up

-she can be alone for significant amount of time quietly (like sometimes more than an hour in her crib or car seat and not cry just sit there alone content

-she slams her feet on her bed in a rhythmic motion

-she does this rocking back and forth motion sometimes very forcefully while she is sitting in a car seat or high chair to the point I’m concerned she is going to hurt herself

-she often doesn’t answer to her name, if it is said many times she may look up but it’s not in the form of responding to being called her name and seems more like just looking at the noise being made

-she hasn’t gained much weight over the last few months

I brought up the back arch thing to my friend who asked her pediatrician and they didn’t seem concerned. I brought it up more than once because it was so odd to me. I have a daughter and other nieces and have never seen these behaviors.

I know you cannot believe everything you read online but so many of the symptoms exhibited are along the lines of spectrum disorder.

I tried to hint to my friend these odd behaviors but she brushes them off. I’m not sure if I should be more straightforward with her so she advocates for her child for answers or leave it be. We are very close —-like sisters and I know the earlier a spectrum disorder diagnosis happens the better the outcome with therapy and treatment. I just don’t want time to go by and be wasted when she could be helped.

Any advice on what I should say or do if anything?

Newborn & Toddlers