Where is her money going? She doesn't have to pay rent (which is often the biggest chunk of someone's expenses). At $40k with 30% to taxes, she should have over $2,000 take home every month.

I know that, I've talked to her about her numbers.

She will have a car payment soon, so let's say it gets knocked down to $1700 including gas and insurance. It might be even lower.

She spends around $300-400 on just like, food and clothes and normal people things. So now we're at $1350.

She will spend $700ish on the loan, as I mentioned in the OP, leaving us at $650.

I want her to pocket at least $500 a month and develop that habit and start saving for a house and everything.

That leaves $150. I bet she is wrong about only spending $400 a month on General Things, and sure, as we watch what happens to her money we can dial up how much she spends on loans.

I sugget she figures out where her money is going first, before you try to finance her loans. If she can't explain how she has no money on a rent-free $40k salary, don't give her any money.

Jeez, every single comment so far. I'm giving her money, I know enough about the situation to think it's the right thing for me and her, and I'm certainly not taking this weird Life Advice based on simple heuristics from people who have read a few words about us.

I want to minimize the interest, and I was asking for options. If there aren't any, fine.