If there is no contact information, start with her colleagues or the place where she used to live. Whether she lives in a factory or rents a house outside, she is registered. Find the supervisor or landlord, check the temporary residence permit, find the ID card, and then determine the home address.
If you graduated from a university, start with the campus network, check the name and school of graduation, find your home page, and find clues from his friends.
……
There are too many ways to find someone. Looking for a needle in a haystack requires thinking and skill.
The possibility of finding it online is too small. As far as I know, migrant workers rarely surf the Internet. Even if they surf the Internet except QQ, online games have nothing to do.
Good luck!