I think she is crazy if she thinks the Legislature can impose retroactive recusal upon the Judiciary. There may be such a thing as recusal, but at the SCOTUS level the decision to recuse resides with the individual justice. There is no mechanism to impose such a thing.
If Rep. Slaughter believes a Justice should be impeached, that can be pursued. SCOTUS Justice Samuel Chase was impeached, but his Senate trial ended in acquittal in 1805.