Было несколько правильных вариантов
- Ей чуть за тридцать. = She is
in her early thirties.
- Ему под сорок. = He is
in his late thirties.
Вот вам еще примеры:
He is in his twenties. - Ему 20 с чем-то (диапазон от 20 до 29).
She is in her early sixties. - Ей чуть больше шестидесяти (60-63).
He is in his middle forties (mid-forties). - Ему около сорока пяти (44-46).
They are in their late fifties. - Им под шестьдесят (57-59)
How old are you?