Anyone out there make a decision to have only one child?

Im wondering if you regretted your decision? how did they fare growing up? Im 40 in november and have been trying for another child. After 2 miscarriages in a year Im at the brink of giving up and getting on with my life. Im feeling guilty for my little girl as Id love to give her a sibling, but Im just not sure i can risk going through another miscarriage... Id love to hear from single child parents and how life has worked out for them