I guess you can try her earlier works? But here's what I recommend~
PLEASE SMILE AGAIN
HimAWArI
As Good As
I HAVE NEVER SEEN
RESPECT the POWER OF LOVE
The SPEED STAR
Violet Sauce (Anotha Recipe)
though they're not really rock...
And by instrumental, do you mean something like Tempest? Well if that's what you meant, then Ningyo is also a great song