Is my husband's ex-wife trying to make me feel bad?

I'm not proud of the way I got my husband. He was married with kids and he and I became friends. I was going through a bad break up and he was going through a tough time in his married so we just clicked. We talked everyday and went to the movies, dinner, shows, basically everything together until the point where we kissed for the first time and made love. He got a divorce because of me but he we still dated got engaged and got married. His ex-wife still shows up now and then and she's surprising warm to me. When she heard I was pregnant the first time she told me that I was a but now that I'm pregnant with his second child she is warm to me and she's telling me everything will be alright and things like that. It's weird to me. It's especially weird that she never addresses by my first name. It's always Mrs. Irvine. Is she trying to make me feel bad?