Before I came to vet school I sat down and crunched the numbers for what different amounts of debt would mean. It was an important part of my decision about whether vet school was worth it financially to me.
The amount of loans that would have minimal to no impact on my family's lifestyle was about $100,000. By that I mean, all the extra income I would make as a veterinarian compared to my previous job would all go to loans for 10 years. If you daughter is single income, that will probably be a different number.
You can estimate a salary here:
What it is Do you want to know the possible salary range of a full-time veterinarian—whether in private practice, academia, government, or elsewhere? The AVMA Veterinary Salary Estimator for Current Students can provide you with approximate salary ranges for full-time work, based on historical...
myvetlife.avma.org
You can estimate a monthly loan payment here:
This Loan Payment Calculator computes an estimate of the size of your monthly loan payments and the annual salary required to manage them without too much
finaid.org
Remember that salaries are going to take out taxes, insurance, retirement, etc. Depending what she decides to do , that'll probably be 25-40% of her salary. So when you are considering the financial ramifications, determine whether it's reasonable to live off of ~70% of the salary minus the monthly cost of the loans.
For a lot of vets who have large debt loads, the answer is no. If you have a $350K debt load for example, 100% of your salary would have to go to the loans on a standard plan. This means they have to seek alternate routes of loan repayment (paying a % of their income for 25 years before the rest is forgiven) or have to make sacrifices to pay it off more quickly (picking up extra shifts, working overtime, no vacations/eating out/extras, living with roommates into their late 20s or early 30s, etc).
For a vet with only $40K in loans. Probably meh? The impact will be something like having a smaller house or delaying buying a new car buy a few years assuming she's going into small animal clinical practice. If she wants to do something that's paid less well (equine practice, rural mixed or food practice), maybe more of an impact but still quite doable.