use the formula A=p(1+r)^n
where
A= value of investment
r= rate
n= time period
p= amount invested
in this question
r= 5.75% but compounded quarterly means divide this by 4
r= 23/1600
n=7*4
n=28
p= $1200
A=1200(1+23/1600)^28
A= $1789.54
Therefore the value of her investment in 7 years is $1789.54