Step mom with momma drama

Just asking for some advice. My step daughter is 4 years old and I’m currently 8 months pregnant with my first. My step daughters mom has full custody and we get her every other weekend and some on Thursdays. Me and the mom have a past before me and my husband even got together and I have never done anything to make her hate me like she does, she just liked a guy that I dated. My step daughter recently started coming home to us and telling me her mom tells her I’m mean and she needs to stay away from me. That really bothers me but what has set everything off is we had her this past weekend and her mom took her to a affordacare clinic after school because of sickness. (I have been there before and told them my symptoms and they did not test me for anything, just gave me medicine for the flu) She proceeded to tell us she had the flu and she was going to get progressively worse. She gave us her medicine and wrote notes saying she wanted peppermint oil rubbed on her daily, she wanted her to take 2 baths to help with fever and she wanted us to take her temperature every hour. She did have a flu shot and all weekend she never ran fever and was acting perfectly fine except for a deep cough and runny nose. We took her back home on Sunday evening and this morning she texted my husband and proclaimed she had a high fever and was taking her to her normal pediatrician. She texted my husband a few hours ago and told him she tested negative for the flu and had bronchitis and an ear infection. She then posted on Facebook and said she had the flu, bronchitis and an ear infection but was so happy she had no fever so far. I feel like she is either lying to us to let her stay with her because she told my husband she shouldn’t be around me since I’m pregnant and she has the flu or she’s posting on Facebook for attention. I’m not sure what to do about all of this! Even though my step daughter is close to me I don’t appreciate her coming over and telling me her mother told her to stay away because I am mean. I also don’t appreciate her mom writing notes and telling us how to treat her when we know what to do.