Here’s a question for those who’ve questioned Jackie Hoffman’s age-appropriateness for ONCE UPON A MATTRESS.

Does it really matter?

True, Carol Burnett was a mere 26 when she originated the role of Winnifred, the medieval-era single lass who’d heard that a nearby kingdom had a marriageable prince. For the 1996 Broadway revival, a pre-SEX AND THE CITY Sarah Jessica Parker wasn’t much older: 31.

To be frank and inelegant, Hoffman isn’t that far from both of their ages put together. And yet, must Princess Winnifred be young? Can’t she be a woman who that feels time is running out and that Prince Dauntless may be her very last chance? Remember, Winnifred is so desperate to become a bride that she didn’t even wait for be castle’s drawbridge to be lowered.

She swam the moat.

Such an action is in keeping with someone who won’t be denied, come hellion (a disapproving Queen) or high water (that moat).

And should we deny ourselves the chance to see Hoffman in a role for which she’s tailor-made just because she’s a few decades late to the party? Consider this non-traditional casting if you must, but here’s betting that after a few minutes in Hoffman’s company, you’ll not even notice that she’s no “poulet de printemps” – partly because your eyes will be half-closed and squinting as a result of the laughter pouring out of your mouth.

Hoffman’s trademark, from HAIRSPRAY to ON THE TOWN, has been her right-down-to-earth and very-no-nonsense attitude towards life. Well, that’s Winnifred, too. Oh, she may be a little misguided in assuming that she’s “Shy,” as her first song goes – for her uninhibited bleats of “SHY!” at the tippy-top of her lungs belies her bashfulness. Director Jack Cummings III sees that Hoffman’s hurricane-gust on the word is strong enough to make the chorus members fall to the floor.

And yet, by the end of the number, everyone has also fallen in love with Winnifred, whose tsunami-level outbursts strike them as a breath of very fresh air.

All right, not everyone. There’s that Queen, one Aggravain. The name fits, for she is quite vain and can aggravate any difficult situation. Here Cummings offers us genuine non- traditional casting in John “Lypsinka” Epperson, the esteemed drag artist. He’s as hilarious as Hoffman, albeit for a different reason: he never goes for camp but plays the Queen (you should pardon the expression) straight.

Epperson’s Aggravain wants everyone to think she’s so dainty that she “applauds” by merely touching the tips of her fingernails on her right hand to those on her left. That’s the extent of her enthusiasm, but not her imperious pretentiousness. She pronounces “dance” as “dahnce” and continues to give many “a”-vowel words get this la-da-dah treatment. Smartly, Cummings doesn’t have Epperson overdo it, but places a judicious interval between each one. That allows us to forget this little quirk, so when Aggravain returns to it, we get a nice catch-us-off-guard surprise.

The real Aggravain, however, reveals herself in an early harangue that may even be longer than the speech King Arthur has at the end of CAMELOT’S first act. The Queen explains to son Dauntless that she puts every would-be- fiancée to an arduous test because she only wants a genuine princess for him. Through 424 non-stop words, she insists that she wants him to marry — until she gives herself away when passion takes over and she moans, “Oh, if I were only 20 years younger!”

Dauntless is smitten with Winnifred, though, so the Queen must make this test the most impossible yet. To determine Winnifred’s “sensitivity” – a must for any princess, Aggravain insists – she’ll put a pea under 20 mattresses; if Winnifred can’t sleep because of the “lump,” only then will she be proved a princess and approved as well. That won’t happen, Aggravain assumes, for 20 firm reasons.

Yes, it’s “The Princess and the Pea” reconfigured into a compound-fractured fairy tale that Lyricist Marshall Barer cooked up with Jay Thompson and Dean Fuller. They did concoct a new complication: no one in the kingdom may marry until Dauntless does. That doesn’t bode well for any courting couple, but it’s especially problematic for Sir Harry (the able Zak Resnick) and Lady Larken (Jessica Fontana, hysterical in both senses of the word). She’s pregnant, which leads to an argument that could end the relationship.

Here’s where Winnifred must put aside her brass-tacks humor and show – yes — sensitivity in getting the two to kiss and make up. Hoffman displays equal tenderness when coping with the neuroses of mother-smothered Dauntless (an appropriately shlubby Jason SweetTooth Williams) and the very hen-pecked, hen-pounded and hen-hounded King Sextimus the Silent (a fine David Greenspan). See? Hoffman can be maternal when she needs to be. And perhaps that’s a quality we associate with someone who’s older than 26 or 31.

What DOES show its age, however, is ONCE UPON A MATTRESS itself. It offers the old musical theater template of two couples – one serious and one comic – alternating scenes. MATTRESS does change the construction: here the romantic lovers don’t dominate with stage time and songs; the funny characters have the most material.

But this Eisenhower Administration-musical has always been held hostage by its antiquated way of changing sets, and Cumming hasn’t found a way to change this. So before almost every new set-up, a curtain is pulled across the stage; the little sliver of floor left in front is where performers do time-killing numbers.

There are quite a few. To be fair, some are quite imaginative, such as “Man to Man Talk” in which the silent Sextimus uses charades to explain the facts of life to Dauntless. Just as much fun is “Very Soft Shoes” in which a second-generation Jester recalls how his father “played the palace.” Cory Lingner gets as much applause with this dazzler as Hoffman does with her big showpiece “Happily Ever After,” in which she examines the fates of other fairy-tale characters.

Mary Rodgers’ music always delights; it even impresses in “Sensitivity,” a rare 5/4 showtune that has Aggravain start out from wondering what she’ll do to Winnifred en route to coming up with her pea-brained solution.

It’s a well-sung revival, which is apparent from the opening number, with Hunter Ryan Herdlicka’s Minstrel managing to deliver his message mock-heroically but with a sterling and astonishing voice.

Most New Yorkers will find ONCE UPON A MATTRESS not easy to find. Transport Group Theatre, one of our premier off-Broadway companies, is renting the Abrons Arts Center on Grand Street. This means an F-train to Delancey Street and a ten-minute walk afterward. But Jack Cummings III’s happy-go-lucky production is worth swimming a moat to see.