Short sleeve or sleeveless with a jacket or sweater, no spaghetti straps.  At one time women couldn't even go to church with spaghetti straps or strapless gowns, it was considered inappropriate.

The first communion is one of the holiest celebrations of the Roman Catholic faith, as well as other faiths.   It is a time when a person first receives the Sacrament of the Eucharist which is the symbol of Christ’s body and blood.  The young person receiving communion is usually about seven or eight years old and has been studying for at least two years, so that they may understand what “being in a state of Grace is” and what “being absolved of all of you sins” means.  They have been baptized, and even if they are not Catholic, they have studied to become a serious member of their faith. These are very serious subjects, even for children at this tender age.  The child will be taking on the obligations and responsibilities of a Catholic, or another faith that celebrates communion, and that celebration of this time should be exemplified by the dress she wears.  It should be pure white and modest in its simplicity.  There should be no frills other then the Vail and white gloves, again pure and simply white and traditional looking.  This is not a time for trendy clothes or for anything too party style.  There is a celebration, absolutely, at a first communion. However,  it is a reverent one and the dress should reflect “a respect for the pureness of the occasion”.