It is so hard when you are from an unconnected, normal, working family and can't afford to do the unpaid internships and so on. In so many fields, it really isn't a meritocracy, at least at graduate level.
The advice I'd give your daughter is.... Think creatively. All the usual routes into popular fields like non-profit are extremely competitive and usually based on doing loads of unpaid work. Play the long game instead - focus on getting a job in any field that will enable her to gain experience and skills that she can later can take into the non-profit sector and be paid well for. Experience in HR, logistics, governance, finance, and lots of other areas, can be directly relevant to NGOs. I would encourage her to explore the other ways people get into the sector. She should research the career paths of senior people in the field - she may be surprised at how many came in from business or via an unorthodox route.
I was in a very similar situation to your daughter a decade ago, in that I graduated with a Master's degree from a well-regarded university and felt a bit lost - I had dreamed of a certain career route but it seemed almost impossible, a road built on unpaid internships and having a "wide network". I got into a bit of a rut, living back at home and not able to work for free.
My Dad urged me just to get any work I could, as it would build up my confidence and get me earning. So I did some odd jobs and then some temp work. That led to me saving a little bit money - but instead of using it to fund a few weeks' working for free, I headed off to Australia on a working holiday visa instead, and managed to pick up some pretty well-paid temp work in a publishing house there for a bit. The work wasn't what I wanted to do long term, but I had picked up the travel bug, some real world work experience, and a lot more confidence.
From this, I applied for, and got, a paid graduate internship in a bank (again, not my preference but enabled me to travel and to gain skills) and this became a full-time position. I made several sideways moves in this firm to gain the skills and experience that would eventually enable me to move (in my early thirties) into the type of work I'd originally wanted to be in, but at a much more senior level.
Ok, it took me a while - but I enjoyed the process. I spent my twenties working in offices across the world, met some great people, and earned enough money to buy a place with my partner in my twenties (which would have not have been possible if I'd been in my preferred field all along, given the low pay). If your daughter is curious and bright (and it sounds like she is!), there are ways she can forge her own path.
Sorry to waffle on a bit - but if I'd known that there were alternatives to ultra-competitive and unfair unpaid internships when I in a post-graduation rut, I would have been a lot more confident in myself and my future.