You are right cwood, no such thing as "too much lift" no.
Writing now as a "general" thread:
But there is a but...
For initial learning some find they are too big and a tad more difficult than our "normal" beginner wing sizes which are also pretty big, because they dont ride so smooth and easy but pops up too fast so to speak.
But in this case this is not an issue as she CAN foil.
Even for experienced there will be a max size that is not interesting anymore when they become too slow turning and too slow riding - but I have no idea at which size this will typically happen for an average weight.
Regarding trim, it depends on the actual hydrofoil.
Whether I use my 1200 cm2 surf wing, or my fast 520 cm2 speed/jump wing, I stand on the same spot on my Ketos.
I got one wing of those in between where I have to stand a few centimeters further back with standard trim but thats it.
So more lift does not necessarily mean you have to stand further forward or move the mast, if the hydrofoil is trimmed neutral (wing position on fuselage and aoa).
On some foils this is the case though, that you have to move feet/mast.
Basically, more lift always means you can use a smaller kite and ride slower when you want, which is the goal besides making everything easier in transitions and maneuvers/tricks
PF