Question 120323
You have to take interest compounding into account. 
Every year, you make interest to add to your sum and then in the following year, you get interst on the new sum, and so on. 
The formula is,
{{{FV=P(1+R)^T}}}
where FV is the future value, P is the current investement, R is the rate of return, and T is the number of time periods.
FV=$2,000,000
R=4.5%
T=45 years
{{{P=FV/(1+R)^T}}}
{{{P=2000000/(1+0.045)^45}}}
{{{P=2000000/7.2482484}}}
{{{P=275928.73}}}
To reach her goal in 45 years, she should invest $275,928.73.