https://morningconsult.com/wp-content/uploads/2019/01/190125_crosstabs_POLITICO_RVs_v1_DK-1.pdf
Page 250. Actually, as it turns out I misremembered. The FOX generation (65+) are the ones who know her best. For every other age group she's essentially unknown/no opinion.
Total Favorable Total Unfavorable Heard Of, No Opinion Never Heard Of
Age: 18-29 27% (92) 4% (50) 7% (59) 42% (46) 347
Age: 30-44 27% (2) 27% (22) 3% (59) 33% (50) 453
Age: 45-54 7% (6) 28% (97) 2% (74) 34% (7) 349
Age: 55-64 24% (9) 28% (03) 6% (6) 32% (8) 373
Age: 65+ 24% (0) 38% (76) 6% (74) 22% (02) 462
Is the age break-down. For most groups close to, or upwards of, 50% either don't know her or have no opinion.
She does better with Dems, but not by a whole lot. Still largely unknown/no opinion.
Everyone whose endorsement could swing the race is running, outside of Obama. That's how wide open this is.