Ответ:

a)

  1. uncle — the brother of your mother or father (дядя).
  2. aunt — the sister of your mother or father (тётя).
  3. cousin — the child of your aunt or uncle (двоюродный брат или сестра).
  4. nephews — the sons of your brother or sister (племянники).
  5. niece — the daughter of your brother or sister (племянница).

b) The female form of cousin is also cousin.

malefemale
brothersister
sondaughter
fathermother
uncleaunt
nephewniece
cousincousin
grandfathergrandmother
grandsongranddaughter