ANSWER:

Of course you are sinning!

You must not chitchat or socialize or be soft while speaking to her at all and must not speak to her except when truely needed about your daughter. 

I have a daughter with my ex-christian wife before I reverted to Islam. I am now married to a Muslim women. I had problems with my ex-wife but I still love her. We always talk sometimes about my daughter but mostly about other things. I want to know what is my limit with this women since she is my non-mahram. Am I sinning for being too friendly with her

Mahram | September 25, 2019 7:41 pm
Previous

If someone remarries and has a child from previous marriage (girl- not adult) Can new husband somehow be a mahram for her or an uncle if she is living with mother and new husband? Although her biological father is still alive. If her biological father passes does new husband become mahram? If her mother has sons from new marriage can they also be her mahram (half brothers)?
Next

My question is that after my marriage, would my father in law be my Mahram? I know for a fact that my brother in laws would be non-mahram, but what about father in law? Can he see my hair?