\[\operatorname{Gi}'\left(0\right)=\tfrac{1}{2}\operatorname{Hi}'\left(0\right)=%
\tfrac{1}{3}\operatorname{Bi}'\left(0\right)=1\Big/\left(3^{5/6}\Gamma\left(%
\tfrac{1}{3}\right)\right)=0.14942\;94524\ldots.\]