Regarding the questions you asked him: there is no objection
to children who are as yet unable to memorize a whole prayer learning certain
sentences only.
He does not feel that the friends should make a practice of
saying grace or of teaching it to children. This is not part of the Bahá'í
Faith, but a Christian practice, and as the Cause embraces members of all races
and religions we should be careful not to introduce into it the customs of our
previous beliefs. Bahá'u'lláh has given us the obligatory prayers, also prayers
before sleeping, for travellers, etc. We should not introduce a new set of
prayers He has not specified, when He has given us already so many, for so many
occasions. (From a letter dated 27 September 1947 written on behalf of Shoghi
Effendi to an individual believer; The Compilation of Compilations, vol. I,
Baha’i Education)