It looks like you’re referring to the classic cumulative nursery rhyme “There Was an Old Lady Who Swallowed a Fly.” Here’s a brief overview and the opening lines of the rhyme:
There Was an Old Lady Who Swallowed a Fly
Summary:
This traditional folk song tells the story of an old lady who swallows
increasingly larger animals to catch the previously swallowed creature,
starting with a fly. The rhyme is often used to entertain children and teach
sequencing and memory skills.
Opening lines:
There was an old lady who swallowed a fly.
I don’t know why she swallowed a fly—
Perhaps she’ll die! Would you like me to provide the full rhyme or a summary
of the story?