Top
立 here is the visual residue of an older
辛 (tattooing knife) — the original
妾 pictured a tattooed female slave-concubine, the brand marking her status. In modern script the top has standardised toward the 'standing' silhouette
立 (5 strokes), absorbing what was once a 7-stroke
辛. Treat as
立 for handwriting.