What should I do with my friend?

I have a friend I met about 5 years ago during high school and about two years into our friendship I got pregnant and had a baby. Even before my pregnancy, my friend who we’ll call Sarah, had some instances that didn’t quite add up regarding her own pregnancy journey. She was very clearly overly interested in having a baby even when we were still in high school. Anyways after I had my baby it was like she became obsessed. Ever since then about every two to five months she’ll come to me claiming to be pregnant but never have any positive tests to show or ultrasounds, just what looks like announcement pictures. I’ll go along with it when she tells me, but then a couple days later we’ll be video chatting and I’ll see her drinking hard liquor and vaping 50 nic and I just don’t say anything. Then she’ll come to me shortly after announcing the “pregnancy” that she’s “miscarried” but her timelines won’t add up. She’ll tell me some ridiculous number like shes sixteen weeks pregnant, but will have told me a month prior she had a miscarriage which isn’t possible. For some reason this going on as long as it has, has started to upset me and I just don’t really know what to do at this point when she inevitably tells me she’s expecting yet again…