It seems the phrase is not in standard English. It looks like it might be a keyboard-mash, a cipher, or a transliteration from another language (possibly Arabic or a similar script written in Latin letters).
"I saw, maybe my heart beat."
She didn’t say it aloud. But the thought arrived uninvited, sharp and true, as if her soul had been whispering it for years without her listening. shft ywnk qlby dq