Hi --- An initial charge order does not give the creditor a right to sell the property, it simply lets the court register the charge against the title documents, so if or when the house is sold voluntarily the debt is cleared from the sale proceeds.
If the monthly payments that a court orders are subsequently not paid, then the creditor could return to the court and ask them to force the sale of the property.......but your Mum will be given every opportunity to pay or object to any decision before this situation would be allowed.
Any payments she agrees to make should be easily affordable and paid on time to stop the charge order being enforced. In a way a charge order is like making an unsecured debt into a secured loan against your home.