Bernie's woes must be also causing a boost here?
It depends on how you're defining Bernie's woes, because there are a lot of them. Since getting in the race, Bernie's support hasn't changed much at all. He's between 12-15% in most reputable polls. The issue for Bernie is he's not even holding onto majority of his 2016 support, and he's literally picked up 0% from 2016 voters who didn't vote for him in the primary. His demographic problems are well known. What's not well known is that he literally only has support in the 18-29 age group. Once you get out of that? He's in the low single digits. (Most recent poll had him running 7th among voters 65+ who make up a far larger share of the electorate than the youths. Warren is currently winning about as large a share of Bernie 2016 voters as Bernie is. She's also winning the most liberal voters. Bernies two stronger bases--youth and independents aren't breaking for him at anywhere near the 2016 margin. And pretty much once you hit 29, his support evaporates.
On top of that he's a 78 year old man who just had a heart attack. Yesterday's polling showed 30% of Democratic primary voters said that it makes them less likely to vote for him. His favorables are down across the board, even in states where he should be doing better than he is. And most of this happened BEFORE the heart attack.
Warren has been gaining pretty widely by getting folks who were undecided to commit to her. She's the only candidate who has moved up in the aggregate week by week. She's doing the hard work of politicking, her favorables are way up, and people like her.
She's the one.