Yasin used to be a sleep fighter too (he's still not the world's best sleeper). I found that it became a bit easier to get Yasin off to sleep after I started following the same pre-sleep routine every time I put him to sleep. My sister used to get her babies to sleep during the day by putting them in thier pram and pushing them back and forwards over a bump on the floor (if there wasn't one there she made one) I did this a few times too and it worked on Yasin. On a couple of occasions when I was feeling a bit stir crazy I put him in his pram and just went for a walk and he went to sleep ok. He still sleeps well in his pram.
He also used to sleep in his sling. Maybe if you have a sling or a hug-a-bub etc you could see if she might drop off in there. I don't think that its a permanent solution but maybe once she's managed to go to sleep a few times without the boob she might be able to go to sleep better in her bassinet.
Good-luck.