Change YW class age criteria?

I'm having to manually change some Young Women so that they are in the younger YW class (Age 12-14) when they were placed in the older YW class (15-18) automatically and overriding the default. These are Young Women who are 14 now. Otherwise I cannot place them into callings into the younger YW class. Is there a way to adjust the age criteria so that the younger class includes all ages THROUGH age 14? Thank you.

General Handbook 11.1.3:

Young women classes are organized by age-groups. An age-group is all young women who will turn the same age during a calendar year. A class may include more than one age-group. Young women progress to a new class in January of the year they turn the age of the young women in that new class.

If these YW will turn 15 this calendar year, then they should be in the 15yo class.

The classes can be combined then split at whatever age is appropriate

The age criterion for a class is set for the age that a young woman will attain during the year as previously mentioned in this thread. That is the default for each class age. The age cannot be changed. For example, the Young Women 15 class will include, by default, all young women turning 15 during the year. Splitting the Young Women 15 class and then attempting to combine one of those two classes with the Young Women 14 class is not possible using the split and combine features. Instead the system will allow manually moving individuals from the Young Women 15 class to the Young Women 14 class. Those young women will now be identified as not being age appropriate for the Young Women 14 class and will have an asterisk to the left of their name. They will not be automatically moved the next year, or any following year. They will have to be manually moved until they are returned to their age appropriate class.

Carefully consider the instructions in General Handbook, 11.1.3, (11.6.2 and 38.8.27, if appropriate). The system is set to follow the General Handbook.

I was invisioning splitting the entire 15 group from the older class and combining it with the younger class.
But you are right that you can't split a single age group and combine either part with anything else,