Corrected entry: When Susan transforms into Ginormica, her dress tears a little, but still manages to stay on and mostly 'grow' along with her. It's a kid's movie, so they couldn't show her in underwear, but it's still a [deliberate] mistake.
The Yeti
10th Apr 2009
Correction: Both Susan and the clothing she was wearing at the time were affected by the Quantonium meteorite, so its hardly surprising both her and the clothing grew together. If the clothing had not grown, then even her underwear would not grow, and she'd be standing naked at 50ft tall.
The Yeti