I can remember what I had to go through, a lot at St Pauls in Bendigo 'confirmation class' where you learnt how to cup your hands properly and to say 'Amen' after the sacraments had been delivered. I just went along with it really.
Its interesting watching my two, Johanna calls it the 'Cup and Bread'. Today when Jemima got delivered the bread and the wine she said very meekly 'thank you', it was ver reverent. Her sister did the same. Strangely I had the urge to correct her to tell her to say 'Amen'.
But then I thought, 'thank you' said reverently, honestly with understanding is probably more honouring to God than a word that is parroted without really understanding.
So yes, I let it go the 'amen'.