The information on Mother's night is pretty sparse, sorry to say.
Mother’s Night
The modern yuletide usually begins for most Heathens with Mother’s Night. In Bede’s De Temporum Ratione he describes what he knows about an old Anglo-Saxon celebration that he states was called Módraniht, which marked the beginning of a new year and was celebrated at the time of Christmas. Apparently Mother’s Night was observed the entire evening through. While little information exists to describe what Mother’s Night was, by looking at the Northern Tradition umbrella we see what appear to be similar rituals. While Yule marks the start of the year for the Anglo-Saxons, we see in Scandinavia that this distinction was at least for some geo-specific locations given to Winter Nights, which had a separate observed ritual to the Disir as part of their celebration. The disir can be understood to be the ancestral mothers, and other female spirits that oversee the family, clan, or tribe. When we reach back to ancient Germania, we also see a thriving cultus dedicated to the “matrons” or the Idis. Female deities are also sometimes included with the disir.
I personally theorize that Saint Lucia’s Day (celebrated primarily in Scandinavian countries, especially Sweden) occurs on December 13th and features a female ‘light-bringer’ may be a Christianized remnant of an ancient disir-related ritual. The Christianized Saint Lucia Day, may have pagan origins related to the figure of Lussi. The practice of Lussevaka – to stay awake through Lussinatt to guard oneself and the household against evil, not only fits symbolically well with a solstice celebration of longest night, but also brings to mind the description of Mother’s Night being observed for the entire night as well.
https://www.deviantart.com/paganarts/journal/12-Days-of-Yule-Mother-s-Night-12th-Night-274797220
