During Navaratri should the kalasam for Thayar be placed first before arranging marapachi (Wooden) dolls? Should women place the kalasam? Can a destitute woman arrange them if no one else lives with her?

Some households follow the practice of arranging kalasam and marapachi dolls. Few other households arrange golu without this practice. There is no prescribed tradition for this. Follow the practice of the concerned household.
Only sumangali or young maidens can arrange the dolls, if no one resides with her then we cannot invite anyone to accept thamboolam. If there are no young maidens or sumangali at home, then the boys at home can arrange the dolls if not any young girls from the neighborhood can be requested to arrange the golu