I think the key here is that she built up $300k of student loans with a 4 year undergrad and up to 3 years (FT) of professional training.
She is only 25 now.. just starting out $30k per year for undergrad, and $60k per year for professional license, plus a bit of interest?
What did she do on summer breaks during undergrad? Seems like quite a lot of cost to the loans, some should be lower?, but this is still at the high end of reasonable if you don't work in summers, did not get grants or subsidies or any parental help (RARE to not get help for low income or any parental cash?). She is absorbing all the costs on her own, which seems a bit off to me.
Average income is $100k-$150k/yr in years 3 to 7 years after graduation. Average income overall is just over $150k/yr.
Not as long as a medical doctor training... not as lucrative... but feasible?