Rather than thinking of phones as home and cell, I suggest that the
solutioon to Cheryle's issue is that she assign the phone number that she
uses to contact a person at in her personal life as the "Primary" number.
Outlook provides a phone type of Primary.  Cheryle could assign a person's
cell or house phone to Primary and have that displayed by default.  Then any
person, not just her Mom, would show up in Outlook in a convenient way.

Outlook provides no way to do that.