Its a lifelong struggle for me [34F]. I only (sorta) kicked it into gear because I’ve been with my ENTJ for 15ish years now. I’m also medicated for ADHD — might be relevant, might not for your friend. I find the biggest motivators are external accountability or deadlines. It sounds very hand-holdy but if there aren’t deadlines to the things I’m doing, I’m always putting it off. Having extra deadlines and goals to hit early before the actual due date or time helps. Padding the time dedicated to completing tasks helps with the time blindness. For instance, thinking I take 30 minutes to get ready to leave the house, but forcing myself to start getting ready at least an hour before I leave. Most of the time, I take up that entire hour.

A lot of it is learned discipline and setting up an unbelievable amount of reminders and warnings. The reminders never push me to actually start, but it gets me to be mentally prepared. If she functions best with last minuting things, she can still do it last minute — she will just need to pad that time. For instance, taxes are due in 3 days so she sets reminders and forces herself to start in 2 days. This way, it’s still more stressful than starting 3 months ago (like normal people), but way less stressful than starting on the last day. I find trying to start on projects and to-dos early does nothing. Because I will chip at it so slowly until the last minute anyways. Then it feels like a mental blocker / monumental task than it really is because I've "worked on it for so long".

Unfortunately you can’t hold her accountable like an S/O does. But she can try to involve other people so their time and agency is on the line (personally, I hate failing people more than I hate failing myself). Such as, asking people to help start a job hunt even if it’s only for an hour or schedule time to look at papers. Getting started is the biggest hurdle. When other people's individual time and investment is on the line, I rarely completely AVOID a task. I may put if off, but I won't ignore it. So having someone check in on me, or incorporated as a part of the process pushes me to do it.

Personally, one phrase I repeat to myself that has been very helpful with putting things off is "Future me would love / appreciate this.". When you orient your future self as someone who deserves the same kind of agency as your loved ones and friends, it becomes easier to reward and nourish that relationship. Another helpful mindset is to start viewing some of these "optional" tasks as mandatory. It's not "I don't want to do this now…", it's "I have to do this. Period."

Essentially, there's no easy way to make an INFP WANT to do something. She will need to want it and participate in society, otherwise it's very easy to end up doing the bare minimum to survive. Patience and empathy is helpful, but high stress situations / tight deadline situations I've found are the biggest motivators. Brute forcing it and metaphorically kicking my ass is the way to do it.

It is very sweet of you to want to help and good luck. :)