Interested to know, what relationship this kindergarten has with Pui Ching? Pui Ching's primary seats match with its own kindergarten. So, even there is relationship, there won't be seats available (not many PC kinder students leave).
Did the staff in this kindergarten tell you there are preferences or you made this assumption yourself?
Honestly, even a primary school with same name may not have preferences for all the students, it is hardly possible there can be preference because this kindergarten are under the same church...... The baptist is not a small organization, so they have many schools under their management.
hope you don't mind me being "long air"! I am glad for you to find a suitable kindergarten eventually.
However, notice you mentioned the relationship with Pui Ching then I was worried you would rely on that so I just wanna clarify that to avoid confusions only (also for other parents' reference).