Should I teach an infant practice Anapana? I want to know what the right age for a child to learn meditation, for example if I do anapana with a toddler, can it stop the development or it will help the child to stay into panya later.

Vipassana courses starts from 8 year old, but that may be due to other reasons, but personally I think I can teach my daughter as soon as possible.

At the time she is less than 3 months old, and she had started making sounds, I know it doesn't make any sense, but this is the age when infants  start to learn and copy things right?

I think if I act like I am breathing my daughter will stop copying me in coming months, so could doing anapana  be good or bad for her?
I have a 17 month old and personally I feel there needs to be an intention to meditate in an individual, rather than blind copying or operant conditioning.. An infant's mind effectively goes through a process of building a self in the first few years and Buddhist thought goes against such a process in a way that I don't think a really young infant will comprehend. Myself, I am waiting till the kid hits 2.5-3 years old, when he will have enough access to language to begin the process of meditation through a personal, conscious choice (if he doesn't want to, then I won't force and will wait!).