I have read a story in Japanese about a taxi driver. It happened that one night he was near the cemetery in Aoyama and he met a young girl, alone. He picked her up and he brought her home. When they arrived she said that she had forgotten her wallet inside her house. She promised the driver to take the wallet and to come back to pay him. Then the story goes on with these two sentences:
しかし、運転手がどれだけ待っても、自宅から女性が現れる気配はない。
耐えかねた運転手がその家を訪問すると、その女性の家族の者と思われる年配の女性が現れ、『あなたが車に乗せた女性客というのは、すでに亡くなっている私の娘のことかもしれない』と告げられる」というものである。
In the first sentence I don't understand how to translate どれだけ in English. In the second one I don't understand why the author put the word 年配 there. I don't understand the meaning of the sentence so I can't translate it.
Thank you in advance for your help!