Just in:

https://onemileatatime.com/reviews/c...-new-york-lga/

Enjoy everyone !

Quote Lucky:
"The Chase Sapphire Lounge doesn’t have shower suites, which is fair enough, since it’s not like most people using a lounge at LaGuardia are coming off a long haul flight."

BUT:

Quote Lucky again:

"Chase Sapphire Lounge New York LaGuardia Reserve Suites

The lounge has three private rooms, each of which can be reserved for a period of three hours for $2,200-3,000
(depending on whether you want a room for four or eight people).
People who book this receive:
a dedicated suite attendant,
a special menu from Jeffrey’s Grocery,
a personal bathroom with a shower,
a signature caviar service upon arrival,
a special wine list curated by Parcelle,
a fully-stocked snack and refreshments center,
and a gift prior to departing"

So it seems one needs to fork out extra or be lucky to gain access to a shower ....