I remember this about the same, but with a few added comments.
In 1946 or 1947, even water war forbidden after midnight on the day you were to receive. On the Sunday morning of our First Holy Communiom, one boy, as we walked by the drinking fountains in the hall, thoughtlessly took a sip. One of the nuns yanked him from the group and sent him to his parents who had already gone into the church. The mortified child had to receive his first Body and Blood of Christ the next week with the general congregation.
A few years later, the water rule was the first to be relaxed although nothing could be added to the water to give it any taste. Other changes quickly followed.