I am sorry for your loss. The answer depends on if she had any assets. If she did not, mail each creditor a short note saying only "My mother died on ____ . She left no assets, so there will be no probate. Please stop sending bills, as there is no one authorized to accept them." and attach a photocopy of the death certificate. After that, ignore them.
However, if she had assets, a probate is necessary and the creditors will be paid ahead of heirs. In that case you should see a lawyer.
