Staff are usually very broadminded and supportive. However your main problem is that you have just under 30 minutes so you may find it helpful to consult me about possibilities within such a time range. The number of expected guests affects what you can do in the time allowed. You can have one burial done anywhere you wish as long as you have the written consent of the owner of the ground. A second burial is not possible without special planning permission to recognise the plot as a cemetery.
Children are a natural part of funerals.
They need to learn about death as part of our life cycle. Keeping it hidden from them magnifies its fearful aspects because they observe that we are hiding a scary secret. For us, children at a funeral remind us profoundly and simply that life goes on through the young. Black is the sacred colour of all transformation so it is not inappropriate, but a funeral is a fine occasion to flaunt one's best in any life colour, to honour the life of the new Ancestor. A wake or funeral feast can be a deeply healing event.