My mom has passed away she left me a house that has a motgage on it. My credit is poor can a quitclaim deed be done to allow me to keep the house .

Hello. I am sorry to hear of your mom's passing.  I am a Maryland barred attorney and practice in this area.   

Any type of transfer can trigger something called a "due on sale" clause which means that the mortgage needs to get paid in full unless the mortgage company approves the transfer.  However, there is a way to deal with this if you cannot pay off the full debt  -- you can try to assume the mortgage rather than apply for a new loan.  The lender should tell you what it requires for an assumption.  

A quitclaim deed simply means the person signing gives up (quits claiming) anything they might have owned - it does not change the mortgage or obligations under the loan.  On a related note, if your name was not already on the title, the personal representative will need to pay off debts and transfer the assets left over as described in the will.  It is not clear from your description what other debts exist, whether there is equity in the home, what other heirs exist or whether the estate is solvent. 

 Please note that this response may not address your specific circumstances and the details of your situation may impact what you can and cannot do.  You may wish to consult with an attorney to help handle your mother's estate.