Very sad , and more so, in that the help when it came (from you) was not accepted.
But not too surprising, i think WGs are less willing to trust help given, than others in society... its as if, they need to be even more clear on boundaries (in terms of keeping their independence) - and this one had been messed about by someone she had initially trusted, so even more likely to be unwilling to accept help from another person, even if it's well meaning....
Some in society who sleep rough, do not want help - im not saying this was the case with her, but just saying that sleeping rough is sometimes seen - by some - as a better option than taking help from another human being, even if it does mean a good night and some 'home' comforts, shower etc.
All in all, a sad story, but not much more you could have done.... I did think offering help was a good thing, especially if it came without strings, and was genuinely trying to be of assistance to the other person. At least you tried.