Family drama, please advise?

Here goes. My neice is 23 , her cousin is 27 and I am 26. We all grew up together , well since I was 13. Anyway both my neice CR and her cousin JC are like sisters to me. CR has been nothing but trouble for my brother and his wife. She dropped out of high school her sophmore year, pregnant by 17, married shortly after, cheated twice, baby by the 2nd cheater, almost divorced. (Through all this I was the only one who still cared, even her mom stopped talking to her ) She ended up staying married and having another baby with her hubby. JC was into drugs, sex, drinking before she hit 15, dropped out of high school, pregnant by 17, baby #2 11 months later, got pregs again and wanted to abort but she was 7 months along and I begged her to consider adoption (Noone even believed she was pregnant and everyone called her a liar) I stood by her and tried to give her other options. She decided not to abort and she had baby girl #3(different dad). She is about to deliver a 4th baby girl with her new man(different dad). I finished high school with honors, went to college, served in the military, married , had 2 sons and I always get treated like the black sheep. My SIL always tells me how dissapointed she is that I didn't finish college, but sings CR's praises. Also CR has a horrible temper so we all walk on eggshells around her, even her mom. And CR and JC always talk about eachother like they are so close even though neither was there for the other.CR told me she would leave her kids to her husbands sister if anything ever happened, that broke my heart. I am godmother to all JC's kids but I don't know who she would leave my girls to. I am sick of it all. How can I stop being the outcast? Thanks for reading, sorry it was so long.