Mom has trouble remembering her phone number. Is this normal aging or is this a sign of mental trouble?

We rarely call ourselves, so when we're asked for our phone number it can take a minute of thought. I wouldn't worry about this one issue as long as she eventually remembers it. However, with Alzheimer's in the family, you (and she) should keep an eye out for other changes.
Take care,
Carol

Thanks Caro, I am just so nervous - she occasionally gives other signs like big memory lapses for past events. She is adamant that nothing is wrong with her and gets very offended when I imply she's having memory problems.