A far shot:

Lottie is most prominently present in Bad Machinery – but

she visits Sheffield once and just before departing tells Daisy that Ingrid is a horrible person she should break up with – which is what Daisy does.

I know in Giant Days Ingrid never learns this and probably never has because only Daisy could tell her.
Furthermore I would rate Ingrind more among the bigger nuisances – on par with Dean- but not a deranged criminal.

But – who knows?