Yup, stretchys only work till about 15lbs on average. As early as 12, as late as 20, depending on the parent, baby, and the wrap.
The time has come, my online friends, to talk of many things:
Of flats, and wool, and hybrid dipes - of breastfeeding and slings-
And why our bed is cramped at night,
and the joy my munchkin brings!