Anyone had super competitive friends?

Ni

So I used to have a friend called N who always had to have whatever I had. This got worse when I fell pregnant with my 1st at 20. She and her boyfriend were going to start trying in 3 months but once I told her I was pregnant, she forced her boyfriend into giving in and began trying for a baby when I was 5 weeks pregnant, only a few days after I told her I found out.

A month later she *still* wasn't pregnant and she got absolutely wasted because she had her period on my 21st birthday and yet I was almost 9 weeks pregnant.

She fell pregnant the next month. She also purchases an engagement ring for herself despite her boyfriend not even proposing, forces him to propose to her on his birthday and then gave birth by being induced because she was sick of being pregnant when I had given birth 2 months earlier & she was again jealous of me.

Fast forward 10 months. I told her that my SO & I were going to start trying for our 2nd and she pretty much immediately started an affair with an old crush (while she was engaged to her boyfriend, baby daddy #1) while planning to break up with him.

So she finally gets the courage to break up with her then fiancé, on the DAY of their anniversary, 1 month after their engagement party/his birthday. That night she has unprotected sex with her side piece and they immediately start dating.

I fall pregnant the following February, when my son is 13 months old. My hCG is 30. N is apparently also pregnant, gets her blood taken & her hCG is only 3. Not even equivocal pregnant. Her tests are negative. I unfortunately miscarry at 5 weeks. She starts her period the next day.

N is so desperate to get pregnant before me that she swings fully into testing with OPKs and conceives the next cycle. She and her side piece/current boyfriend get engaged after 3 months of dating. They break up briefly when she is 9 weeks and she goes out and gets absolutely smashed for 3 days in a row. Then claims on Facebook groups that she "didn't know she was pregnant before drinking", unsure if her fuck up would cause her baby to have severe issues. I'm so over her shit that I purposely don't get pregnant until 6 months later.

I cut off the friendship 2 months later  because I am so over her constant manipulation, narcissism, lying, cheating and controlling behaviour.

I give birth. I find out 2 months later that I am pregnant again & it's twins. She finds out through stalking me and decides to get pregnant again. (Her mother still calls me regularly and keeps telling me about her life even though I've told her several times that we aren't friends). I give birth a month before her.

I fall pregnant 7 months after giving birth from my twins (planned). She finds out again and is so desperate to have another purely because I'm pregnant again that she stops breastfeeding and puts her child on formula. She is either pregnant again or trying to conceive.

Why the fuck is she so competitive? It's not just with kids, she has been like that throughout the entire time we were friends. I just don't get it. Is she THAT insecure about herself, that she'll never be truly happy unless she has 'more' or 'better' than others do? Like Christ, she needs therapy bad.