Don't use this, this sounds more like "how much power do you have within your family?" Simply ask, "are you the youngest in your family?"

Hi Maria. As a native English speaker, I would understand what you meant. However, it also could imply a social standing in the family. I think it would be better to say something like, "Where do you fit into your family?" That immediately implies to me that the person is asking about the family's hierarchy by age.

i am the youngest one from 2 others

I think it's better If you say that, What's your position(or number) in your family?

This question is somewhat vague. It could have multiple meanings. Like where do I stand in my family? Financially, age,gender whose the happiest. You should be more specific so the more suitable question would be, how old are you compared to your siblings?. Or another way to say it would be. are you the oldest or youngest in your family? Hope this helped