Riot Matchmaking LUL

I'm silver 2 atm, I think High gold MMR but regardless I am put up against a Gold ADC and Plat Supp with an unranked Supp whos MMR is in no way close to silver. I went through her match history post game and she didn't have a single win where she had a positive K/D (she mains mid lane) and her losses were even worse. I'm jw honestly how she was put into this game. Granted this was norms but I'm pretty sure its not supposed to be completely random matchmaking in norms.