Let them do it their way and express themselves. It will create interest in it for them. This is also a good way to develop them spiritually and in self confidence. They should be encouraged in what they do or say and not be belittled. Have the family altar when it is most convenient for all.
Supper time is usually best for all before the various activities of the evening begin.
Possible methods that may be used. Paragraph Bible study. Rather than read a whole chapter at a time which may be quite long and hard to retain, do just a paragraph a day. Let all the members of the family suggest a title to the paragraph according to its content. Let each one list some things they observe in the paragraph such as places, people, things, special words, etc.