Monterey or Santa Cruz... (more)

I am trying to plan a week that will entertain my elder mother (85 yrs old) and my 7 yr old son. She lives in the SF Bay Area. I would like to plant my mother in a rocker on the deck or in front of the window overlooking the beach, while my son and I rent bikes, kayaks, explore tide pools, etc. So what do you think - Santa Cruz or Monterey?