Galactus special rules states that:

"Galactus ignores the Exploit Weakness, Force Blast, Incapacitate, Mastermind, Mind Control, Plasticity, Poison, Psychic Blast, Shape Change, Stealth, and Support powers of opposing characters, as well as team abilities and effects that duplicate the effects of those powers."

Also, it says that:

"Characters and tarrain do not block, or impose the hindering terrain modifier on, lines of fire drawn to or from Galactus."

Invisible Woman (Secret Invasion) SP states that:

"Any character that is 7 or more squares away from the Invisible Woman can't draw a line of fire to her."

Suppose she's standing 8 squares away from Galactus, gets her range perplexed up to 8 or 9, then takes a shot at Galactus. can he shoot back?

No he couldn't see her. She doesn't duplicate stealth, it's her own special power. He ignores stealth and powers that duplicate stealth AKA Batman Team Ability. He does not ignore her special power

This was similarly discussed about Thunderer of Qward and Darkseid's special power. Would Galactus ignore the penetrating damage from these figures because he ignores psychic blast and the answer was no he didn't

double post

Sue doesn't have Stealth. Nowhere does it even reference Stealth. That's like saying "Galactus ignores RCE" and using it to justify Galactus ignoring because they both modify. Galactus ignores Stealth, which Invisible Woman doesn't have. Simple solution, Sue's safe.

The poor fool who Perplexed her instead of running, however, probably isn't safe on the next turn.

Comic Panel #1: huge burst of energy from Galactus' hand
Comic Panel #2: close up of Invisible Woman's face looking appalled and shouthing "Reed!"