Ah, the treacherous labyrinth of romantic gift exchanges!

1) She need not feel any embarrassment about her gift not matching his in its monetary worth, and it would reveal his true colors fast if he makes an issue out of it. Gifts should be thoughtful, appropriate and within the means of the gift-giver; it's folly in any situation (romantic or not), in my opinion, to do the sad calculus of "what will they spend on me, I have to make sure mine matches."
2) However, she has excellent instincts that it's way too early, in terms of what they're doing, not in terms of time, to give such a significant present. I gather they are in the early stages of da
ting; he's jumping way too far ahead. Some of those early stages are fun! He's leaving himself no where to go.

She should return it with, to quote Miss Manners, a mouth that says no but eyes that shine.