Hi Irma, I felt so sad reading your post. My x had little to do with his children after he left as they disowned him. I tried to get them to see he left me not them, anyway after many years and a family crisis he asked me to see if they would let him email them, eventually they did and he met up with each child. After all the times I tried to get them to forgive him the first time they met it hurt so much and I was cynical. He sees them briefly once a year now. We are just as close as we ever were and I feel happy knowing that they have at least a sort of contact. His new wife never is mentioned or visits, but I know how you feel but you are the adult and must be the bigger person.
Do not let this woman have any power over how you feel or live your life. It was along time ago now.I doubt that you are even mentioned in their lives or considered. Do not give her any satisfaction that she has control over you. What have you done wrong to be ashamed of? nothing as far as I can see. If you really are happy with your life then live it and be the best mum you can be. Gosh half the women in the world would be living behind closed doors if you had to hide to avoid wife number 2. Is your God not capable of giving you grace and strength to overcome both jealousy and fear? I know mine is and yours is too, just ask and be strong.
Count your blessings and have a happy and joyous new year.