Do you other children pick up some of your child's autistic traits?

Yes. I have a 5 year old with PDD-NOS and he is sensitive to loud noises - things like applause or the vacuum, or singing (not on his terms). So my 2 year old will sometimes react to things the way that he does... like she'll cover her ears or say "no singing please". Good, bad, or autism related she will do whatever her big brother does.. simply because he is her big brother. At this stage in the game she doesn't really "get" that he acts a certain way because of being autistic. All she sees is "hey my big brother who I worship to no end is covering his ears... I think I'll cover mine too.". I don't sweat it because she's just trying to be like him and doesn't show any other signs.

Hi! I think you hit the nail on the head when you used the work mimicking. That's all your little one is doing. She just thinks that's what should be done since she sees her older brother doing it. When she gets older, she will understand that he flaps his hands because he is autistic, not because everyone does it. She will learn there is a difference. I hope that helps! :-)

My older son doesn't mimick his younger brother, who is Autistic, but I would say that I don't think it is that odd. Like the other posters have said - kids mimick, especially the behavoiur of their older siblings. I wouldn't worry about it unless there were other signs in your younger daughter.

They can't get the same trait if they were not born that way. You just have to tell the other kid to stop and eventually she will grow out of it and be herself instead of doing what the others do. Kids do things all the time that they see others do.