Psycho MIL

I think my psycho MIL sent my husband’s ex girlfriend my way to get information about my child. Background information: My husband had this girlfriend from 13-16 and they were child-hood friends, first loves blah blah blah basically she ended up cheating on him with one of his best friends. Flash forward to now, my husband is 22 and I’m 23 we have a 3 year old daughter. A few months ago I get a Facebook messenger message from my husband’s ex saying things like “hey I’m ____ idk if you know me but I have a kid the same age as your kid” now I understand not wanting to post your child on social media but this account of hers hasn’t been updated since 2016 and there was not a SINGLE sign of a child. Also “coincidentally” her “child” was born on the exact same day my daughter was born. Now I know my husband wasn’t unfaithful because my entire pregnancy he was at home with me and we also lived over 1,000 miles away from her. Now I read this text and I’m like my husband never contacted her, I’ve never contacted her. I’ve never even met her. Only one who LOVES her is my MIL. My MIL absolutely hates me (she has said everything hateful under the sun to me. About my family, about my heritage, about me as a mother, about my loyalty to my husband, it’s a real life Reddit story) because I’m not his ex. I will stand up to her when she’s wrong and out of line and I will speak my peace and be heard. Anyway she was asking me all these questions about my daughter and asking for pictures and what not, I may be over thinking but we’ve been NO CONTACT with my MIL for a solid year now and low contact with her the year prior. So she knows little to nothing about our daughter and maybe has seen our daughter 4 times in 3 years. I just want to know what others think about this. Am I overanalyzing this? My husband knows about this text from his ex and said it’s probably his mother’s doing.