[quote=@Dedonus]
<Snipped quote by Tearstone>

[b]Arachne[/b]:  "Can that shrink ray produce isolated effects?"

[b]Athena[/b]:  "You do remember that you have an advanced healing factor, right?"

[b]Arachne[/b]:  :(
[/quote]

Technically even with a healing factor depending upon which technology the shrink ray uses say like Pym Particles Arachne could use it to reduce her bust. Since it only changes the distance between atoms and not the atoms itself. Although there is a downside, her new bust might be where her collarbone is since there's no way to ensure her breasts will reduce in size properly. They might become oddly deformed or worse misaligned to her body. Try finding a bra in your size that cups your new bust at that height.