how do i track family tree free?

[Nicholas]

my step daughter want to no if she has any sibblings from her natural father, he says she has a brother and sister but cant remember their names as he has not seen them for many years and is now losing his marbles what is the cheapest and best way to see if they exist?
i have details of the natural father and the sibblings are around the age of 20 - 30 years old

[Maxi]

Without a full name you are not goinfg to find anyone, let alone a minor ( if they are minors) living people have privacy rights so you are not able to look at records of living people...............

ADD: As I said living people have privacy rights, so with a full name you can look at phone books, electoral rolls and social media websites, without a full name you can't find anyone

[Fanaticalhair981]

Your query has nothing at all to do with a family tree, which is all about who a person's ANCESTORS are: their mother, father, grandparents, great-grandparents, etc., all the way back to Adam & Eve.

All fathers are natural; SciFi keeps talking about creating or cloning people, but none so far (that I know of).

So, go to whatever place maintains birth records there and check with them. Perhaps the local (local for where the father lived) has birth announcements? Check all the various sources that might have birth records. Other than that, try some social sites, such as Facebook.

Or hire a detective.