According to Bede, the year pre-Christian 'English' (Anglo-Saxon) year began on Modranecht or 'Mother's Night' which coincided with the Roman, Christian, date of 25th December.  I don't think think there's anything mysterious about that, it's well known that the Christian calendar merrily adopted any pre-existing festivals that seemed to fit and then 'baptised' them.

However, the writer of the reflections uses this as a way in to reminding ourselves that God is  beyond gender, either binary or as a continuum, and too mysterious for our comprehension.  After millennia of male dominated god-language, maybe it's good to remind ourselves of feminine words too, not to replace but to peacefully coexist...

The prayer for today

Loving God, who is beyond gender, and so can be my heavenly Mother as well as my heavenly Father, may I know your mother's love this day, may I know that wonderful connection that is only possible between a mother and her child between you and me.  Be with me this day, O wonderful Mother God. Amen.