Shallow veins

Toddler who is almost 3 years old, female, 12kg, no medication or medical history, fully vaccinated- has these purple/ blue like patch’s on her leg, which go more of a red colour after something like a bath. It’s only on one leg. Not a rash or eczema. Has been there since about 8months old. Have shown well child nurse who wasn’t concerned but said to show doctor next time she’s there. But she’s never needed to go. I’m wondering if it’s just shallow veins on that leg 🤔