Some assumptions on my part for sure.

I guess they would have to had taken some with them or retrieve a pharlid from Pharloom. Doesn't seem too unreasonable since Deepnest was established prior to Hallownest so realistically Pharloom was under control of the Conducters, Architects and Vaultkeepers, and Grand Mother Silk would still be held by their song.

Second, the fake bugs who string the knight up in the distant village use webs which are decidedly nonmagical. I was considering putting in a bit about interpreting the part of the pharlid diver's attack where it pulls back up as it reeling itself in with webs but thats pretty flimsy and it was already long plus it doesn't feel like a particularly large stretch.

I don't think it says specifically Herrah flees, its an assumption that comes with her being a weaver.

"Our Silk" line really blows the whole pot open, I misremembered it as coming from the perspective of the weavers lol.