Grandchild dependent- My question is, my grandchild lived with me for 7 mts. The other 5 mts with her mother. Her mother has already filed her taxes. I have provided all of her care. Can I still claim her even though her mother has already? without penalt

[MargaretL]

No, you cannot.

The IRS allows to claim a dependent only once.  If you do claim the grandchild and his mother has already done so, your return will be rejected. 

If you believe that you qualify -and not your daughter - to claim the child, you would have to mail your tax return with proof showing why you are entitled to claim the grandchild (school records, medical, support).  It would take a long time for the IRS to process your return.  They literally look at the proof and decide who should claim the child.