Confuse in a confusing situation ?

My fiance and i are living together for 4 years now. We are getting married next year. He was a divorcee for more than 7 years (they have children) and they remained friends to-date . I don’t mind him still communicating with her (even the rest of their lives  ) because they have children. My fiance and I have a good happy relationship and also blessed with a child. The problem arises when his ex-wife relationship with the boyfriend of 7 years ended. Phone calls and emails to my fiance become frequent, asking about how our family are doing, and worse asking when will she be the stepmom (jokingly??) I don’t know, but surely not a good joke! I could understand if the emails are about their kids but to ask what’s going on with our life is totally none of her business. My fiance suggested to meet her in order to avoid any jealousy which I agreed. Meeting her only makes me look at her differently….she always tried to approach my fiance when he is by himself. This is making me and my fiance uneasy.