If you were to look for 1/3 scale weapons, you might have a hard time finding any. There's a Katana at Volks USA, a few weapons are listed but are out of stock at Volks Japan, and you might be able to find 1/3 scale military rifles at various retailers. I personally feel finding 1/3 scale weapons is difficult, expensive, or both. This led me to consider alternatives.
To the right is a pair of Gundam themed chopsticks I purchased at a Gundam Cafe in Japan. They set me back 1080 yen. At the exchange rate as of this writing, that's about 10 USD. If you want to copy what I did, I realize this is not helpful for those who don't live in Japan or don't have plans to visit. However, my point is to show alternate methods for providing your daughters with the kinds of weapons worthy of their psychopathic tendencies.
I will also use a Gundam Marker for this project.
Where you can buy markers (Amiami): Pour Type | Liner Type
Right: How it comes from the factory
Left: Touched up with the Gundam Marker
Darth Sheryl is here!
"BIIIIITCH! No one wears my clothes but me!"