How did Conan not recognize Ran’s mother?

I think the first time we as viewers were introduced to Ran’s mom was in the coffee shop murder case. But it also seems like that was the first time Conan met her as well? He didn’t recognize her until Ran showed up and let him know she was her mom. Was Eri & Mouri’s divorce that long ago? Shinichi & Ran were close childhood friends, so it just didn’t make sense to me that he didn’t recognise Eri in this episode. Am I missing something?