I think it was about a four year relationship with Jagger. Very unfortunately everyone in that milieu "did drugs" and she succumbed and became addicted and more or less stayed addicted for a long time , on and off.
She led a difficult ( despite her great beauty , possibly because of it) life very bravely, I think.
I didn't like her voice when she was younger but the older voice was quite well suited to the materiel that she later performed.
RIP Marianne.