Social service letter

Today I got a letter asking me to be a foster parent to a child who would be 6th cousin to my children and 5th to my husband ( at the time I got the letter I had no idea who the child was until I talked to my FIL) I called the case worker and told her I have no clue who the child or people are and my husband don’t even know who the parents are I was told to sent if back saying no relation to child but all day my mind has been on the 3 yr old boy who need someone to care and love him and I wish that people could be is but we live in a 2 bed room house with 2 kids already of our own. I wish I could so more. Sorry had to vent cuz it’s been on my mind all day.