Aisling and Sunday School

There is no nursery program at the church we attend. That's probably a big reason why there are few families with young children in attendance, except on Baptism Sundays. Sunday school is in place for children 3 and up, so long as the three year-olds are toilet trained. Both Devlin and Ceilidh seem to enjoy Sunday school as they both run off happily to their classrooms. Aisling gets stuck with sitting with us for the remainder of the service.
However, around Christmas time, she started to go into the class with Ceilidh. She would sit next to her big sister, and mimic the song actions, and also partake in the crafts. Aisling even took part in the Sunday school choir and the Christmas pageant. So, why, was she kicked out of Sunday school class yesterday? After weeks of attending with Ceilidh, the teacher decided to impose the "must be 3 years old" rule, even though she is completely toilet trained, and we've never seen or heard of any behavioural/listening issues about her.
Poor Aisling. When she was unceremoniously shown the door, she had a HUGE tantrum. All she wanted was to be with her sister Ceilidh, sing and colour. Along with the other children, and few toddlers. After Daddy calmed her down enough to come back into the church sanctuary and sit with Mommy, there were still tears in her eyes. She was subdued, but kept muttering "No" to every question. She even turned down a package of smarties!
As the sermon dragged on, Aisling became antsy, and the "No" chorus increased in volume. Time for a walk around the church. We ended up by the Sunday school classroom. Aisling tried to open the door. "I want to be with Ceilidh!" she cried.
I don't know why the teacher decided to not include Aisling in the class, but I will have a word with someone. The day was ruined for Aisling. "I don't like church" she announced as drove home. "I can't go to church school with Ceilidh."
When the nation's churches are hurting for members, this is not the way to encourage young families from rejoining the congregational flock.