A girl is swinging seating in a swing. What is the effect on the frequency of oscillation if she stands?

Time period of swing $\mathrm{T\alpha }\sqrt{\mathrm{l}} ..\left(1\right)$
If a sitting girl stands up in a swing, then centre of mass raised up and length of the swing decreases then the time period of swing decreases
But $\mathrm{n\alpha }\frac{1}{\mathrm{T}} ...\left(2\right)$
$\therefore \text{ From (1) and (2) n }\mathrm{\alpha }\frac{1}{\sqrt{\mathrm{l}}}$
then frequency of swing increases