Unless the cheque is very large (triggering money-laundering precuations) you can make it out to cash, or you can make it out to yourself, and present it at her bank for payment. If a cheque has not been crossed, the bank on which it is drawn is obliged to cash it. If they don't know you personally, they can require proof of identity.
You are lucky that your mother is willing and able to help you out. Remember that when she is old, and might need your support.