She can make 2 hats.
Since she can make 3 hats in 1.5 hours, divide 1.5 by 3 to find the unit amount of hats she can make.
1.5/3=.5
.5 of an hour is 30 mins.
Now, multiply 30 mins by 2 to find the amount of time it would take to make 2 hats.
30*2=60 or 1 hour.
She can make 2 hats in an hour.
Hope this helps!