Both Jena and May have baby-like personalities, but

It feels like Jena's cute personality just comes out because she's young and the youngest,
whereas May's personality itself is just a bit baby-like and has a cute side.
I heard that when the agency CEO first introduced Jena and May to each other, he whispered to Jena that May is a baby-like person, but Jena didn't understand it at all.
If Jena weren't the youngest in another group, she has the kind of personality that could have played a mature role quite well, and if May were the oldest in another group, she would have immediately become the "oldest-youngest" (matnae).