Aoife does tell us that Scatty is a liar and shouldn't be trusted when asked about her and Scatty's ages:
I don't think Scatty ever lied about her age. She's been truthful. She had said that she'd hung out in Shadowrealms where time flowed differently so she only counted her years on Earth. Aoife just happened to count all
her years, everywhere.
(To be honest, I think Aoife in that scene was trying to burn some bridges to try and keep Scatty to herself by saying that she was a liar and wasn't to be trusted. I don't think Aoife has any real love of humani and she probably wants Scatty to be the same way. In essence, I think she was jealous in that scene.)
This isn't really in response to anything specific, more a theory.