生母和后母
When the mother was treating his son's tumefaction on his head, there was a lot of blood coming down from the top of her son's head to the neck, forming a cruel scene. But the people watching this all considered this to be an act of solicitude done by the mother to cure her son as soon as possible, and it's done out of love for the son.
If a stepmother had done this, then people would have considered the stepmother to be so cruel that she had the heart to do so. People might even think that all stepmothers hoped the children of her husbands former wife would die soon.
母亲在给儿子治疗头疮的时候，血从孩子的头顶一直流到耳朵根，景象非常残酷，但看到的人都认为是母亲希望儿子病快好所采取的关怀行动，是爱孩子太深的缘故。
如果这做母亲的是后妈，那看到的人则会认为天下做后娘的确实残忍，因而敢下手。他们或许还会联想到做后妈的都想让前妻的孩子赶快死掉。