I need some help, /n/.

Girlfriend is 5'4". She bought a hybrid bike from Walmart (Schwinn Network 3.0). It's a little too big for her, but she doesn't want a new bike.

Could I replace the suspension fork with a rigid fork to lower the height of the bike so she can comfortably stand with the bikes? Will this mess with the riding characteristics enough to matter?

She isn't a triathlete, she just wants to ride around town sometimes. So its more about comfort than anything.