Aaah~, yeah that

Turned out Saber was building a Mordred statue

Yeah

So, there's currently an event held in FGO right?

That's just simply what she has to do to see the event, so you don't have to think much about it

She destroyed that statue she just built.

But, afterwards...

She even made lots of excuses but as I thought she has something on her mind concerning Mordred.

and that also means she's an idiot(loving & passionate) parent.

It simply means that she continued to construct buildings Mordred demanded in her first play-through

I fear there's some sort of feud between them that a person like me could never understand...

But it's not just the statue, she then continued to destroy all Mordred-related facilities!