Answer:
At any time t, her altitud will be given by the following law:

Step-by-step explanation:
We can consider the gymnast as a point particle in the position of her center of mass. The law of movement will be:

where g is gravity's acceleration which we can take as
. We add 0 in the last member just to note that at
the vertical position is 0. If we knew that she was moving at
at
, we would have needed to put 1m in the place of 0.