baby mama legal advice needed

Sa

hey ladies i need some advice. my fiance has an insane baby mama. i dont know what her deal is but im very creeped out and feel invaded. my fiance and i are getting narried 1/2 and once that happens he will go on my insurance. when i add him to mine i planned on adding my step son as well because hes currently on child health plus and the support order says he cant be on CHP once eother parent can provide insurance. fiance contacted sons mother filling her in and she snapped saying no spewing crazyness. instead of arguing we responded we will have our lawyer contact yours. like 1hr+ later she responds about "his girlfriend" had to take out assistance when she bought her house in addition to the mortgage and then was all id like to see the application how much dis she lie on that. now baby mama works not for the irs but a company who helps people with irs stuff. im beyond upset and creeped out that she looked up and got and has that info. idk if that info can be found online or if she abused her power at work but i dont wanna let this go. thoughts?