I don't think there's any reason to worry about this.
Haven't they booked her more dates in the Summer? To me, that's not a sign she's underperforming.
It's her 3rd leg. JLo has a brand new show and she's doing promotion rounds on TV.
It'd be more fair to compare her number's to Britney's:
Britney Spears The Axis at Planet Hollywood Las Vegas, Nev. Feb. 13-14, 17, 19-20, 24, 26-27, 2016 $4,007,691 28,540 /
34,488 8 / 0 $495, $179, $94, $54 Caesars Entertainment
That's 82% of occupancy.