As the policy advisor for the Federal Reserve during the time period shown in the graphs, I would implement monetary policy when there are signs of economic instability or imbalances. For example, if I see a sharp increase in inflation rates or unemployment levels, it may indicate that the economy needs intervention.
One point at which the Federal Reserve might act is in Q2 of 2019 when the GDP growth rate shows a significant decrease in the graph. This could be a sign of economic slowdown or recession, prompting the Federal Reserve to implement expansionary monetary policy to stimulate economic growth. One step the Federal Reserve might take is to decrease interest rates to encourage borrowing and spending.
Another point for intervention could be in Q3 of 2020 when both unemployment and inflation rates are high in the graphs. This may indicate stagflation, a situation where there is high inflation and high unemployment at the same time. In this scenario, the Federal Reserve might implement contractionary monetary policy to address inflation pressures. One step they could take is to increase interest rates to reduce borrowing and inflation.