You appear to each onlooker as their own mother - including race, height, weight, size, facial features, clothing, sound of your voice, hair length, coloration, and distinguishing characteristics. Your statistics and attacks do not change, and you cannot use this spell to gain abilities like water-breathing or flight. A viewer who has no mother, or who never met their mother, may see another parent, a mother figure they have known, or an impression based on their concept of motherhood.

A creature can use its action to inspect your appearance, and must succeed on an intelligence/investigation check against your spell save DC.

When you cast the spell, choose one of the following options, the effects of which last for the duration of the spell. While the spell lasts, you can end one option as an action to gain the benefits of a different one.

Mother's Love. Essentially Bless - up to three targets granted Mother's Love can add 1d4 to an attack roll or saving throw.

Mother's Disappointment. Essentially Vicious Mockery - you're not mad, you're just disappointed. If the target can hear you (though it need not understand you), it must succeed on a Wisdom saving throw or take 1d4 psychic damage and have disadvantage on the next attack roll it makes before the end of its next turn.

Mother's Fury. You grow claws, fangs, spines, horns, or a different natural weapon of your choice. Your unarmed strikes deal 1d6 bludgeoning, piercing, or slashing damage, as appropriate to the natural weapon you chose, and you are proficient with your unarmed strikes. Finally, the natural weapon is magic and you have a +1 bonus to the attack and damage rolls you make using it.

Shoutout to Nathan M. for conceptualizing this spell!