After having been regressed by the Time Stone, Black Widow (or rather, 'little Tasha' as Hawkeye had annoyingly started to call her) was put in the care of S.H.I.E.L.D.'s babysitting facility D.A.Y.C.A.R.E. while the other Avengers searched for the Time Stone to age her back to normal.
Tasha had insisted on participating in the search, but the others would have none of it. She nearly threw a tantrum then, but reminded herself that the worst thing she could do in this situation was act like a baby and be treated like one. So when they decided to put her in D.A.Y.C.A.R.E. for the time being till they could find the Time Stone, she calmly accepted it - like an adult.
Of course, it didn't quite register with her that as a baby, she needed a complete wardrobe change. So when the nanny bots came, she wailed and flailed as they diapered her, braided her hair into pigtails, slipped on booties, and threw on a frilly dress - which Tasha later discovered after much pulling and tugging, simply could not cover her exposed diaper. She must have been really loud, because next thing she knew, her mouth was stuffed with a pacifier.
Later, after she had calmed down somewhat, she glanced around to take a better measure of her surroundings, noting possible methods to escape, absentmindedly sucking on her pacifier. She may lack the body for acrobatics now, but she still had her wits and her tiny size could prove useful.
She just hoped she could find a way out while her diaper was still dry...