Participant    Age    Type
   John         5      A
   John         3      B
   John         3      B
   John         3      C
   John         4      B
   Amy          5      A
   Amy          3      A
   Amy          4      C
   Amy          4      B

ggplot(data = df1, aes(x = Type, y = Age, color = Type)) +
  geom_point() +
  geom_count() +
  facet_wrap(~Participant)