Hmm, just an idea but what are the tooltip settings in nUI for your wife's computer ? There are 3 settings and I believe one of them places it halfway up the left hand side. Maybe one of the other settings will suit you more or maybe you could change the following to suit your needs if the 3 options don't work for you. I'm sure Scott will be able to say whether it is the best file to change or if there is another I missed.
Folder: nUI\Integration
File : nUI_Tooltips
The SetPoint function itself may be what you can change to suit your needs.
Code:
elseif nUI_Options.tooltips ~= "default" then
nUI_SavedTooltip_SetDefaultAnchor = GameTooltip_SetDefaultAnchor;
nUI_SavedTooltip_SetOwner = GameTooltip.SetOwner;
nUI_SavedTooltip_SmartSetOwner = SmartSetOwner;
GameTooltip:ClearAllPoints();
GameTooltip:SetPoint( "LEFT", WorldFrame, "LEFT", 0, 0 );
nUI_Movers:lockFrame( GameTooltip, true, nUI_L["In-Game Tooltips"] );
nUI_Movers:lockFrame( GameTooltip, false, nUI_L["In-Game Tooltips"] );
-- manage tooltips
hooksecurefunc( "GameTooltip_SetDefaultAnchor", tooltipSetDefaultAnchor );
GameTooltip.SetOwner = tooltipSetOwner;
SmartSetOwner = tooltipSmartSetOwner;
end