Breach of promise

Hello .. Kindly guide me in this case. My cousin was dating a girl and met her may be just 5 or 6 times and wanted to get married to her but she had never shown the concent to get married and was giving it time by just dating. They din had any physical relationship meanwhile and din't even promised to her family regarding the same. He was still talking to his ex girlfriend at that time in some ways. After a while when he realised that she is not compatible with her for marriage he broke up and moved on with some other girl and is still with her. But now this girl is calling him again and again threatening to give her money for everything she spent when they were in relationship and even went to his house with her friend and few more strangers in his absence and tried to threaten them to pay the money or she will file a complaint against him. She had been calling his parents and family members as well threatening about the compliant to police if when they agreed to pay her asking some time. Apparently she got in contact with my cousin's ex girl friend as well and they both started asking for money for even all the expenditure done by them when they were in relationship. They are adults and independent individuals when they were dating. Can she really file a complaint on the basis of breach promise when she was the when who started bothering his family members after break up.