She should go with Deal 1 because Deal 1 is greater than Deal 2 by $3.75.
We can represent Deal 1 as a geometric sequence:

The 0.25 is the first term, 2 is the common ratio (it doubles every day) and n is the term number.
To find the total amount of money for this, we would find the sum:

When we evaluate this sum, we get 31.75.
Deal 2 can be represented as 4(7) = 28.
This makes Deal 1 31.75-28=3.75 larger than Deal 2.