My son has primary legal custody of his 7 year old daughter. He recieves S.S.I. and he and his daughter my grandchild live in mine and my husbands home and have always lived here since she was born. parents divorced in 2014.. Mom moved out and she has shared legal custody and visitation. neither pays any child support... We provide all needs for grand daughter ( 7 yrs old) Housing, food ,heat, clothing ect. She has not spent one night with her mother since the 1st week in august... Then we still had her at least 5 nights a week.....My son can not file as his only in come is S.S.I..... Mom is claiming granddaughter as a dependent on her Income tax she only worked a few months. But wants the tax refund for the child credit.. is this legal. Would we have the legal right to claim her as she is supported by us and lives full time with us?

