Opinions on my story plot? say if i should change anything!?

Starts off with the girl slipping and almost falling off a cliff, the guy manages to grab her before she tumbles over the 60ft drop. The girl asks the guys name so that she can buy him a coffee to thank him for saving her life. The pair meets and has coffee and seem to get on really well, so the guy asks her out on a date and she accepts. They date for a few months before falling uncontrollably in love with each other. After a few months they decide to take their relationship to the next level and move into a house together. The mother of the girl isn’t happy about it and tries to make her daughter see sense and not leave home, they argue and fall out and don’t speak again for a while. One year after the near death experience the guy asks the girl to marry him and she accepts and receives a very costly diamond ring. The daughter invites her mother to the wedding but she doesn’t turn up. They find out soon after the wedding that they are going to be having twins, a boy and a girl. A few weeks after the twins are born the guy and girl take a romantic stroll along the beach to watch the sunset but all goes horribly wrong as they were both shot by her mother, the girl is in a comma for 2 weeks with her sisters and friends around. The guy is in a comma for 2 months and needs a kidney transplant or he will die. A friend offers his kidney but isn’t a match leaving the guys only hope to be that a kidney comes up and saves him. The girl is heartbroken and doesn’t know what to do cause the man she loves is on the brink of death. Eventually after a few days a kidney becomes available and he pulls through. The result being both of them live there life in fear and the girl buys a gun to be safe.