A moment of sadness · 5:35pm Jan 31st, 2015
I've gone over the canon in my story, and it all points toward a time between S3 finale and the S4 opener.
So...
Episode Maud Pie hasn't happened, so I can't (easily) use Maud Pie in The Monsters She Lost.
Maud is one of my favorite characters too, so that's a shame.
But how about this for a possibility?
Liz's team is scattered all over Equestria right? So it's not beyond the bounds of possibility that Maud could encounter one of them, & since Pinkie could've told Maud about Liz & her team a letter, she directs the Pokemon in Liz's direction. Once the Pokemon reaches Liz, they tell her that they were helped by Pinkie's sister, but no further details, which preserves the later canonical first meeting of Maud & the Mane 6.
Could that work? I don't know if this is your intention, but I would love to see Maud encounter a rock-type. Such a meeting might excite or astound her enough to raise a whole eyebrow.
Alas (and small spoilers) Omastar is Liz's only rock type. If I had known Maud would be a thing back when, I would have set it up and she'd be studying in... Baltimare! And then she'd get to poke the rock-shelled nautilus.
"Sedimentary. Not limestone. Not sandstone. Not mudstone. Not shale. Not breccia or chert. It's a kind of rock completely unknown to science."
"Calm down, Maud! I've never seen you so shaky!"
*A single hair on Maud's head moves maybe one millimeter*