
What if the lip stick stick runs out?

That'd be counterproductive to the plot if that was possible. And if it was true anyways i'd be very disappointed at the mangaka.

Maybe when it runs out, that is the last face she can have until she too succumbs to death and a new one is mysteriously made for her child.
100 100 we finally reached one hundred! ε=ε=(ノ≧∇≦)ノ