Adding on an AP?

[wdwrule]

Our family has premiere annual passes and for an upcoming trip, son’s girlfriend will join us. We’re staying 4 days and debating whether to just get her day to day park to park tickets or get the power pass (don’t want her blocked out of Studios during Mardi Gras concert days, otherwise we’d consider season pass). I also thought of getting discount tickets then upgrading them to power pass at hotel ticket desk. Any opinions on this as to which would be financially wise? There’s always the possibility of her joining on some future trips as well.