Both son and mother compulsory heirs of deceased father

Dear PAO,

My aunt is a widow. She and my uncle were married for 20 years prior to his death in 2007. Now, she is dating her high school friend. My cousin and I have been talking and she is really concerned about her mother getting married again. If that happens, will it affect my cousin’s right over the properties left by her father? What can she do to protect her rights? Will she also need to change her surname? Your prompt response will be highly appreciated.