i think the best way to deal with friends who constantly ignore your advice is to just let them go through their own emotions. You have given every advice you think is best for her, and yet she still chooses to ignore it. The only thing we can really do as friends is standby and let it happen, but just remind her that you will still be there even through all of this, because in the end she will learn whats best for her with or without others telling her. She will in the right time realise why you have been giving these advice, and if she values you as a friend then she will consider how this is affecting you as well.

i hope this helps