User blog comment:Hitsuji Mamoru/Servant Creation Room 2 : Guess of the Who/@comment-28209369-20170802025757/@comment-28209369-20170803102321

I have a feeling you might be getting closer. Yes, yes she is from that time period. And yes, her other swords are also well-made even though not on the same level of her Noble Phantasm.

One last hint is that she didn't historically have three swords, but she did have two. My version only has three because she is unwilling to wield her Noble Phantasm unless needed, so there is another sword to make up for it.