She did not say the phone was on her bedroom, she said she talked to him on the phone in her bedroom. If you recall those days we all had like 30 foot long handset cords so you could walk away from where the phone was jacked to the wall. I didn't have a phone in my bedroom but I talked on the phone a lot while sitting in my bedroom. And I am the same age as this woman.
Not even a good try.
We never had any 30 foot cord on our phone. In those days, most parents wouldn't allow their kids to yak on the phone in their bedrooms where they couldn't hear what was being said. Why would her mother point out that she didn't have a phone if it was still possible that she could use the family phone in her bedroom?
Furthermore:
"She says she talked to Moore on her phone in her bedroom, and they made plans for him to pick her up at Alcott Road and Riley Street, around the corner from her house."