Lovely Mess

The bat lady's song, Messmer's entire Crusade, all those conflicts to establish the Erdtree, shows her anger, and the cruelty she's capable of:

Then there's Shaman's village, the clinic underneath Shadow Keep, the golden braid, the Minor Erdtree, the sealing of Death - that points to grief, trauma, survivor guilt, kindness, and the ruinous drive for revenge that results in the above path down hell:

(there's also a theory for the Crusade's headless statue being a reminder for the Hornsent of what they put Marika's mother through, but it's not concrete canon so here is the link if you want to check it out)

The fact that all of Erdtree's incantations are heal and protection spells (with only one exception of Wrath of Gold spell which was found after the Elden Ring was shattered), the Capitol's Perfumers originally being blessed healers, and that all Erdtree blessings come in the shape of tears give the picture of Marika's gentle wish at the beginning: to heal everything and everyone.

(and to me personally, there's a kind of vulnerability and honesty in showing your tears to the world and let it be your power to heal at the same time.)

the eye she blessed Messmer with (i do think the Eng translation at some part lost the sentiment of the JP text - that the eye is always referred to as a blessing)

the blessing flask that - unlike its Dark Souls equivalent (which ranges from 6-13 flasks), only have 4 available to us player, heal all ailments and status effect, and specified as sth made for Messmer.

the Marika's soreseal in the Haligtree + the waterfall near Godwyn's final resting place

the Regal Omen Bairn (that was fashioned after the Jizo statue - sth made by grieving parents wishing for protection for their deceased child in the afterlife)

the blessing, gifts, equipment that Messmer and Godwyn's personal knights all get

the fact that Marika's bedchamber and the Impaler's Catacomb (which is the only catacomb in the base game to have the spike trap mechanic used in catacombs in the DLC) remain the proof of Messmer's existence in the base game

how Godwyn's ending is the only ending where the mending rune is placed on the position of Marika's womb (the lower arc or the Elden Ring - also referred to as the basin in which its blessings pool)

that's a whole barrage of motherhood. the love, the fear, the postpartum depression, the guilt and anxiety, (the occasional scheming for revenge with her son). and despite how flawed and tragic that love ends up being for all of them, it is there.

(there's a whole subplot about how Messmer is the only demigod to be called ugly in-game (Hornsent npc dialogue) while Boc's questline is about how his mother being the only one to always assure him he's beautiful, despite everyone else calling him ugly. and how each NPCs questline does reflect a wider theme seen in Marika and her children. but again, i digress)