Is it possible for a human to have a sigil?
You can make them… Typically using as much of the persons name you can find out.
Personal sigils are very powerful though, and all care should be taken to make sure they never fall into the wrong hands. I believe S. Connolly calls them your Power Glyph in one of her books.
If you are meaning, make a sigil for someone else, by tracing their name on the Rose Cross, for example, then sure. You can evoke living people so why not?
I’ve never tried it though, but I would expect the result to be simply an aspect of that person, rather than the whole. EA has said he can feel it when people evoke him, so make a sigil and give it a go
You might also try approaching the person’s Higher Self, and asking it to provide a sigil.
Should i paint that sigil on the puppet of the target person? her real name from birth?
You could, yes. Treat it as you would the sigil of any spirit.
If you know their date and time of birth you could use this even.